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Archive-name: medicine/asthma/general-info
URL: http://www.radix.net/~mwg/asthma-gen.html Posting-Frequency: monthly Last-modified: 17 September 2000 Original-author: Patricia Wrean <prwrean@sfu.ca> Version: 5.3 See reader questions & answers on this topic! - Help others by sharing your knowledge
alt.support.asthma FAQ: Asthma -- General Information
======================================================
Introduction:
------------
Welcome to alt.support.asthma! This newsgroup provides a forum for
the discussion of asthma, its symptoms, causes, and forms of treatment.
Please note that postings to alt.support.asthma are intended to be
for discussion purposes only and are in no way to be construed as
medical advice. Asthma is a serious medical condition requiring
direct supervision by a physician.
This FAQ attempts to answer the most frequently asked questions about
asthma on the newsgroup alt.support.asthma. It was compiled by Patricia
Wrean <prwrean@sfu.ca> and is currently maintained by Marie
Goldenberg <mwg@radix.net>. The Asthma Medications FAQ is also posted
monthly as a companion to this one. For information about allergies,
please see the alt.support.asthma FAQ: Allergies -- General Information
(still under construction), and its companion posting, the Allergy
Medications FAQ.
Please be aware that the information in this FAQ is intended for
educational purposes only and should not be used as a substitute
for consulting with a doctor. Most of the contributors are not
health care professionals; this FAQ is a collection of personal
experiences, suggestions, and practical information. Please remember
when reading this that every asthmatic responds differently; what is
true for some asthmatics may or may not be true for you. Although
every effort is made to keep this information accurate, this FAQ
should not be used as an authoritative reference.
Comments, additions, and corrections are requested; if you do not wish
your name to be included in the contributors list, please state that
explicitly when contributing. I will accept additions upon my own
judgement -- I'll warn you right now that I'm a confirmed skeptic and am
not a great believer in alternative medicine. All unattributed portions
are my own contributions or those of the original maintainer, Patricia
Wrean <prwrean@sfu.ca>.
+ = added since last version
& = updated/corrected since last version
======================================================================
Table of Contents:
-----------------
General Information:
0.0 Changes since the last version
1.0 What is asthma?
1.0.1 What is chronic asthmatic bronchitis?
1.0.2 What is status asthmaticus?
1.0.3 What is anaphylactic shock?
1.0.4 What is COPD?
1.0.5 What is emphysema?
1.0.6 What is bronchitis?
1.0.7 What is pneumonia?
1.0.8 What is cystic fibrosis?
1.1 What is an asthma attack?
1.1.1 What is wheezing?
1.1.2 Do all asthmatics wheeze?
1.1.3 What is "coughing asthma"?
1.1.4 Is asthma hereditary?
1.2 How is asthma diagnosed?
1.2.1 What is a spirometer?
1.2.2 What is a peak flow meter?
1.3 How is asthma normally treated?
1.3.1 How is an acute asthma attack treated?
1.4 What are the most common triggers of asthma?
1.4.1 What is intrinsic/extrinsic asthma?
1.4.2 Can gastric reflux trigger asthma?
1.4.3 What is occupational asthma?
1.5 Asthma and Pregnancy
Medications:
2.0 What are the major classes of asthma medications?
2.1 What are the names of the various asthma medications?
2.1.1 Are salbutamol and albuterol the same drug?
2.1.2 Can albuterol be taken while taking salmeterol?
2.2 Are some asthma drugs banned in athletic competitions?
2.3 What kinds of inhalers are there?
2.3.1 Do inhaler propellants bother some asthmatics?
2.3.2 What is a spacer? What is a holding chamber?
2.3.3 What is "thrush mouth" and how can I avoid it?
2.3.4 Is Fisons still making the Intal Spinhaler?
2.3.5 What's the difference between Spinhalers and Rotahalers?
2.3.6 Why are so many asthma drugs taken via inhaler?
2.3.7 How can I tell when my MDI is empty?
2.3.8 Are my aerosol inhalers going to disappear?
2.4 What kinds of tablets are there?
2.4.1 Why do I need a blood test when taking theophylline?
2.4.2 Why are combination pills not commonly prescribed?
2.5 What is a nebulizer?
2.6 What medications should asthmatics be careful about taking?
2.6.1 What about corticosteroids and chicken pox?
Miscellaneous:
3.0 What resources are there for asthmatics?
3.1 Where can I get the latest copy of the FAQs?
3.2 What is an FAQ, anyway? What is a Usenet newsgroup?
+ 3.3 How about some other WWW links?
List of Contributors
References
Disclaimer
======================================================================
0.0 Changes since the last version
-----------------------------------
September 17, 2000
------------------
Asthma Gen: Added 3.3 WWW links section
Asthma Gen: Added reference to Living Well With Asthma book
Asthma Gen: Added reference to The Doser (inhaler counter) in section 2.3.7
Asthma Med: Added reference to Advair (salmeterol / fluticasone)
Asthma Med: Added reference to Bambec (bambuterol)
Asthma Med: Added reference to Combivent (ipratropium / salbutamol)
Asthma Med: Noted that Bronkaid and Isuprel appear to have been
discontinued in Canada
Asthma Med: Added reference to Xopenex (levalbuterol)
Asthma Med: Added reference to Oxeze (formoterol) turbuhaler
Asthma Med: Added reference to Pulmicort neb soln available in US
September 17, 1998
------------------
Asthma Med: Added note that Foradil (formoterol) now available in Canada
February 17, 1998
-----------------
Asthma Med: Added Serevent Diskus, Flovent Rotahaler, Pulmicort,
Airomir, Tilade nebulizer solution, and Singulair
(newly approved medications)
Asthma Med: Added note that Medihaler-Epi has been discontinued
Allergy Med: Added note that Seldane has been discontinued
Allergy Med: Added Nasonex (newly approved medication)
Asthma General: Added section 1.4.3, Occupational asthma
December 6, 1997
----------------
Asthma General: Split web version of FAQ document into multiple-page
format.
August 17, 1997
---------------
Asthma General: Added section 1.5, "Pregnancy and Asthma"
Asthma General: Added reference to new version of NHLBI report
Asthma General: Added reference to Adams book
Asthma General: Correct reference to Gershwin to reflect 2nd edition
June 17, 1997
-------------
Asthma General: Correct publication information on "Children With
Asthma" by Dr. Plaut
Asthma General: Added links to archived version of Allergy
Medication FAQ
May 17, 1997
------------
Asthma Med: Added note that Nasalcrom now Over-The-Counter (OTC) in US.
Asthma Med: Added Zyflo to Leukotriene Receptor Inhibitor section
Asthma Med: Added Proventil HFA MDI
Asthma General: Added discussion of phaseout of CFC
(chlorofluorocarbon) MDIs
Asthma General: removed comment that "both spinhaler and rotahaler are
available in the US" (the spinhaler is not available in the US)
1.0 What is asthma?
--------------------
Asthma is best described by its technical name: Reversible
Obstructive Airway Disease (ROAD). In other words, asthma
is a condition in which the airways of the lungs become
either narrowed or completely blocked, impeding normal
breathing. However, in asthma, this obstruction of the lungs
is reversible, either spontaneously or with medication.
Quickly reviewing the structure of the lung: air reaches the
lung by passing through the windpipe (trachea), which divides
into two large tubes (bronchi), one for each lung. Each
bronchi further divides into many little tubes (bronchioles),
which eventually lead to tiny air sacs (alveoli), in which
oxygen from the air is transferred to the bloodstream, and
carbon dioxide from the bloodstream is transferred to the air.
Asthma involves only the airways (bronchi and bronchioles),
and not the air sacs. The airways are cleaned by trapping
stray particles in a thin layer of mucus which covers the surface
of the airways. This mucus is produced by glands inside the
lung, and is constantly being renewed. The mucus is then
either coughed up or swept up to the windpipe (trachea) by
cilia, tiny hairs on the lining of the airways. Once the
mucus reaches the throat, it can again be coughed up or,
alternatively, swallowed.
Although everyone's airways have the potential for constricting
in response to allergens or irritants, the asthmatic's airways
are oversensitive, or hyperreactive. In response to stimuli,
the airways may become obstructed by one of the following:
- constriction of the muscles surrounding the airway;
- inflammation and swelling of the airway; or
- increased mucus production which clogs the airway.
Once the airways have become obstructed, it takes more effort
to force air through them, so that breathing becomes laboured.
This forcing of air through constricted airways can make a
whistling or rattling sound, called wheezing. Irritation of
the airways by excessive mucus may also provoke coughing.
Because exhaling through the obstructed airways is difficult,
too much stale air remains in the lungs after each breath.
This decreases the amount of fresh air which can be taken in
with each new breath, so not only is there less oxygen
available for the whole body, but more importantly, the high
concentration of carbon dioxide in the lungs causes the blood
supply to become acidic. This acidity in the blood may rise
to toxic levels if the asthma remains untreated.
1.0.1 What is chronic asthmatic bronchitis?
--------------------------------------------
Chronic asthmatic bronchitis is the condition in which the
airways in the lungs are obstructed due to both persistent
asthma and chronic bronchitis (see sections 1.0 and 1.0.6).
People with this disease generally also have a persistent
cough which brings up mucus. Chronic asthmatic bronchitis
which also involves emphysema is usually classified under
the more general category of COPD.
1.0.2 What is status asthmaticus?
----------------------------------
Status asthmaticus is defined as a severe asthma attack that
fails to respond to routine treatment, such as inhaled
bronchodilators, injected epinephrine (adrenalin), or
intravenous theophylline.
1.0.3 What is anaphylactic shock?
----------------------------------
Anaphylactic shock is defined as a severe and potentially
life-threatening allergic reaction throughout the entire
body. It occurs when an allergen, instead of provoking a
localized reaction, enters the bloodstream and circulates
through the entire body, causing a systemic reaction.
(There may also be an intrinsic trigger, as some cases of
exercise-induced anaphylaxis have been reported.)
The symptoms of anaphylactic shock begin with a rapid
heartrate, flushing, swelling of the throat, nausea, coughing,
and chest tightness. Severe wheezing (asthma), cramping, and
a rapid drop in blood pressure follow, which may lead to cardiac
arrest. Hives and vomiting are also common features. The
treatment for anaphylaxis is intravenous epinephrine (adrenalin),
with antihistamines and steroids also being used in selected
cases. Aminophylline may also be given for pronounced asthmatic
reactions that do not respond to epinephrine.
1.0.4 What is COPD?
--------------------
COPD is chronic obstructive pulmonary disease, also known as
either COAD, for chronic obstructive airway disease, or COLD,
for chronic obstructive lung disease. COPD is a disease in
which the airways are obstructed due to a combination of
asthma, emphysema, and chronic bronchitis. The 1987 Merck
Manual notes that "the term COPD was introduced because these
conditions often coexist, and it may be difficult in an
individual case to decide which is the major one producing
the obstruction."
[Maintainer's note: the entries for COPD, emphysema, bronchitis,
pneumonia, and cystic fibrosis have been included because of
common confusion between the various diseases which can affect
the lungs.]
1.0.5 What is emphysema?
-------------------------
Emphysema is the disease in which the air sacs themselves, rather
than the airways, are either damaged or destroyed. This is an
irreversible condition, leading to poor exchange of oxygen and
carbon dioxide between the air in the lungs and the bloodstream.
1.0.6 What is bronchitis?
-------------------------
Bronchitis is an inflammation of the bronchi, the large airways
inside the lungs. (Bronchiolitis is the inflammation of the
bronchioles, the small airways.) This inflammation often leads
to increased mucus production in the airways.
Bronchitis is generally caused either by a virus or by exposure
to irritants such as dust, fumes, or cigarette smoke. If caused
by a virus, the bronchitis will likely be only temporary. In
the case of prolonged exposure to irritants, particularly
cigarette smoking, if there is permanent damage to the bronchi,
bronchitis may become chronic.
1.0.7 What is pneumonia?
-------------------------
Pneumonia is an infection of the lung tissue. In adults, it is
generally caused by bacterial infections, though viruses, fungi,
and protozoa may also be culprits. The latter microorganisms
have become very common as causes of pneumonia in immunosuppressed
persons, such as those with HIV infection. However, for those
with chronic illnesses, especially cardiac or respiratory
diseases, or those at increased risk for pneumonia, there is a
pneumococcal pneumonia vaccination available as a preventive
measure for the most common of these bacterial infections,
streptococcus pneumoniae. In children, pneumonia is most
commonly caused by viruses.
1.0.8 What is cystic fibrosis?
-------------------------------
Cystic fibrosis is a disease in which excessive amounts of
unusually thick mucus are produced throughout the body.
Because this mucus production also occurs in the lungs,
people with cystic fibrosis are extraordinarily prone to
bacterial infections which result in progressive lung damage.
Cystic fibrosis can be diagnosed by a "sweat test" as people
with cystic fibrosis have elevated chloride levels in their
perspiration. This condition often resembles asthma in
children.
1.1 What is an asthma attack?
------------------------------
An asthma attack, also known as an asthma episode or flare,
is any shortness of breath which interrupts the asthmatic's
well-being and requires either medication or some other form of
intervention for the asthmatic to breathe normally again.
1.1.1 What is wheezing?
------------------------
Wheezing is the whistling or rattling sound that occurs when
air flows through obstructed airways. At the start of an
asthma attack, wheezing usually only occurs while exhaling, or
breathing out, but as the attack progresses, wheezing may
then be heard both while inhaling and exhaling. If after
the attack progresses further, the asthmatic then stops wheezing,
this may indicate that many bronchioles (small airways) have
become completely blocked, which is a very serious condition.
1.1.2 Do all asthmatics wheeze?
--------------------------------
No, not all asthmatics wheeze. Although wheezing is extremely
common in asthmatics, in _All About Asthma_, Dr. Paul says,
"It is important to note that not all asthmatic symptoms need be
present for one to experience an asthma attack. For instance,
not all asthmatics wheeze. And sometimes wheezing is so slight,
it can only be heard with a stethoscope. With some asthmatics,
coughing is the only symptom present." Similarly, in _Children
with Asthma_, Dr. Plaut states that children with chronic coughs
"may have asthma even though no wheezing is present." He
diagnoses such children with asthma if their peak flow improves
when given an inhaled bronchodilator.
1.1.3 What is "coughing asthma"?
---------------------------------
In _Children with Asthma_, Dr. Plaut defines "coughing asthma"
as "a form of asthma in which coughing is the only symptom and
there is no abnormality in any lung function test." This
condition is also known as "cough variant asthma." Coughing
asthma often improves when standard asthma medications are
taken.
1.1.4 Is asthma hereditary?
----------------------------
No, asthma itself is not hereditary, but there does seem to be
a hereditary component to the tendency to develop asthma. In
_All About Asthma_, Dr. Paul states that if neither parent has
asthma, the chances of each of their children having asthma are
less than 10%. When one parent has asthma, the chances rise to
25%, and when both parents have asthma, the chances climb to 50%.
(Actually, there is considerable disagreement among my sources
as to the exact numbers, but all agree that the chances climb
dramatically if one or both parents have asthma.)
Similarly, if one or both parents have allergies, the chances
of each of their children having allergies are 35% and 65%,
respectively, compared to a less than 10% chance if neither
parent has allergies.
However, Dr. Paul cautions that "children don't inherit asthma
itself, but the tendency to develop it." Whether or not an
individual develops asthma is also influenced by their exposure
to various other factors such as infections, irritants, and
allergens.
1.2 How is asthma diagnosed?
-----------------------------
Asthma is diagnosed based on a physical examination, personal
history, and lung function tests. The physical examination looks
for typical asthma symptoms such as wheezing or coughing, and the
personal history provides additional clues such as allergies or a
familial tendency towards asthma. Although lung function tests
have not always been used for diagnosis in the past, the NHLBI
Guidelines for the Diagnosis and Management of Asthma state that
"Pulmonary function studies are essential for diagnosing asthma
and for assessing the severity of asthma in order to make
appropriate therapeutic recommendations. The use of objective
measures of lung function is particularly important because
subjective measures, such as patient symptom reports and
physicians' physical examination findings, often do not correlate
with the variability and severity of airflow obstruction."
Lung function tests may be as simple as measuring peak flow with
a peak flow meter, or using a simple spirometer, or may involve
a battery of spirometry tests in a pulmonary function lab.
1.2.1 What is a spirometer?
----------------------------
A spirometer is a machine for testing lung function that you
breathe in and out of through a hose attached to a mouthpiece.
You are usually given nose clips so that all the air you breathe
goes through the machine. One I've been tested on had a little
expanding tank surrounded by water into which the air goes, and
I could see the top rising and falling as I breathed out and in.
It can measure a fair number of characteristics of your lungs,
including FVC, FEV1, and PEPR. FVC, or forced vital capacity,
is the amount of air that you can exhale forcefully after taking
a deep breath. FEV1, or forced expiratory volume in one second,
is the amount of air that you can be exhale in one second.
Peak flow, or PEPR, is described in section 1.2.2.
The sophisticated spirometers I've seen have a PC attached, and
have neat little curves generated with each breath, which
apparently have characteristic shapes for different respiratory
diseases.
There is a slightly less sophisticated machine that I've blown
into, and I'm not sure if this is also classed as a spirometer or
not, but you take a deep breath and blow into it, much like a
peak flow meter, except that it draws a little graph of how much
volume you've blown out, and I'd imagine that you can get the
FVC and FEV1 off this graph.
For more information, I recommend the book by Drs. Haas,
_The Essential Asthma Book_, which goes into more detail about
the various things you can find out from spirometry.
1.2.2 What is a peak flow meter?
---------------------------------
A peak flow meter is a little plastic device which you blow hard
into, after having taken a deep breath. It records the rate at
which you've blown into it in litres exhaled per minute (L/min)
-- this is called the peak expiratory flow rate (PEF or PEFR).
The meter is essentially a cylinder with a mouthpiece at one end,
a place for the air to escape at the other end, and a calibrated
meter along the side. When you blow into it, a marker is pushed
along the scale and comes to rest at a point which indicates your
PEF. Since you want to measure your maximum peak flow, it is
important to take a deep breath and blow as hard and as fast as
you can. Many asthmatics find that their maximum peak flow provides
a good objective measure of how their asthma is doing, so peak flow
meters now are used extensively for self-monitoring of asthma, and
also for monitoring the effectiveness of asthma medications.
1.3 How is asthma normally treated?
------------------------------------
Treatment of mild asthma usually tries to relieve occasional
symptoms as they occur by use of short-acting, inhaled
bronchodilators. Treatment of moderate or severe asthma,
however, attempts to alleviate both the constriction and
inflammation of the airways, through the use of both
bronchodilators and anti-inflammatories. Bronchodilators are
drugs which open up or dilate the constricted airways, while
drugs aimed at reducing inflammation of the airways are called
anti-inflammatories.
Taking anti-inflammatory drugs (usually inhaled corticosteroids)
daily for moderate to severe asthma is a relatively new approach
to treating asthma. The idea behind it is that if the underlying
inflammation of the airways is reduced, the bronchi may become
less hyperreactive, making future attacks less likely. Such
anti-inflammatory therapy, however, must be taken regularly in
order to be effective.
For asthma which is strongly triggered by allergies, allergen
avoidance can often greatly reduce the amount of medication
needed to control the asthma. Taking anti-allergic medications
or taking shots for allergy desensitization are other
alternatives. For more information about allergen avoidance
and allergies in general, please see the alt.support.asthma FAQ:
Allergies -- General Information (still under construction).
1.3.1 How is an acute asthma attack treated?
---------------------------------------------
An acute asthma attack is usually treated with bronchodilators
to reduce the constriction of the airways. Intravenous adrenalin
and theophylline are often given in emergency rooms for this
purpose, if short-acting bronchodilators given by nebulizer
haven't sufficiently controlled the attack.
Once the acute attack is over, anti-inflammatories may be used to
reduce the inflammation of the airways. Inhaled steroids are
usually the first choice, but for a sufficiently severe attack,
oral steroids such as prednisone may also be given.
1.4 What are the most common triggers of asthma?
--------------------------------------------
The most common triggers of asthma are:
- viral respiratory infections, such as influenza (the flu)
or bronchitis;
- bacterial infections, including sinus infections;
- allergic rhinitis;
- irritants, such as pollution, cigarette smoke, perfumes,
dust, or chemicals;
- sudden changes in either temperature or humidity, especially
exposure to cold air;
- allergens, for people with allergies;
- emotional upsets, such as stress; and
- exercise.
1.4.1 What is intrinsic/extrinsic asthma?
------------------------------------------
Intrinsic and extrinsic asthma are outdated terms which have now
been replaced by terms related to the asthma trigger, since the
inflammatory response of the airways is the same independent of
the cause of the asthma. What was known as extrinsic asthma is
now called allergic asthma, while asthma triggered by non-allergic
factors, formerly called intrinsic asthma, is separated into such
categories as exercise-induced asthma and occupational (chemical-
induced) asthma.
1.4.2 Can gastric reflux trigger asthma?
----------------------------------------
Yes, gastric reflux can act as an irritant which triggers
asthma. Reflux, properly known as gastroesophageal reflux,
occurs when the liquids in the stomach pass up the esophagus,
or feeding tube. Because these liquids are usually highly
acidic, they can irritate and inflame the esophagus, and
also the airways of the lung, should any of this liquid be
aspirated. This irritation can trigger an asthma attack.
Asthma flares caused by reflux are more common at night,
for it is easier for material to pass up the esophagus when
one is lying down. Some simple treatments to prevent reflux
include raising the head of the bed, not eating close to
bedtime, or using either antacids or medications such as
ranitidine (Zantac) which reduce the amount of acid produced
by the stomach.
Contributed by: Betty Bridges bcb56@ix.netcom.com
1.4.3 What is Occupational Asthma?
-----------------------------------
Occupational Asthma is asthma that is caused by sensitization from
exposures in the workplace. Asthmatics whose asthma is exacerbated by
exposures in the workplace would not be classified as having
occupational asthma.
There are over 200 substances that have been documented as causing
occupational asthma, but there are probably more that have not been
recognized. The substances that are known to cause occupational asthma
can be divided into two main categories.
High molecular weight proteins of animal or plant origins are common
causes. Things like animal dander, flour proteins, and animal scales
are frequently causes of occupational asthma. These same things are
also common causes of non-occupational asthma. These are usually
IgE-mediated responses.
Low molecular weight chemicals that have the ability to bind with
proteins or act as haptans are causes of occupational asthma. There
may be other mechanisms involved besides the classic IgE-mediated
responses as not all those that are sensitized have specific
antibody production. Reactions may have reflex, inflammatory,
pharmacological, or immunologic pathways or a combination of several.
Often occupational asthma is difficult to diagnosis. There are may be
immediate, late, or biphasic reactions. In late reactions the symptoms
may not occur until away from the work place. Frequently the asthma
worsens as the workweek progresses and improves over the weekend.
Treatment for occupational asthma is basically the same as any other
asthma with a few very important exceptions. For those that have
chemically induced asthma from sensitization to that chemical;
avoidance of the trigger is essential. While steroids and other
medications are helpful in treating the symptoms, they do not
prevent the underlying sensitivity from increasing.
Once sensitized to a substance, some react to minute amounts. Levels
below current TLV levels still trigger reactions. For a sensitized
individual any exposure can cause symptoms.
Continued exposure to the triggering chemical can cause permanent lung
damage, chronic asthmatic conditions, and even death. Medication
should never be used to allow the worker to continue to work in an
environment where there is exposure to the triggering substance. Early
recognition and removal from exposure is essential in preventing long
term disability from asthma.
Chemically induced asthma can occur both in the workplace and outside
of the workplace. There are many exposures outside of the workplace
that there are exposures to chemicals that can induce asthma. Most
physicians are not familiar with this type of asthma. For anyone that
has chemically induced asthma, avoidance of the trigger is essential.
1.5 Asthma and Pregnancy
-------------------------
Many people have posted to ask about whether it is safe to become
pregnant while suffering from asthma, and in particular whether it is
safe to use their asthma medications while pregnant.
The general consensus (from the doctors I have consulted) is that
asthmatics can safely become pregnant without undue worry about whether
the mother and the baby will be all right. Most doctors talk about a
"rule of 1/3" by which they mean that roughly 1/3 of all asthmatics get
better while pregnant, 1/3 stay the same, and 1/3 find their asthma is
aggravated (I improved with one pregnancy, and stayed the same with the
next).
In any event, the bottom line when pregnant is ensuring that the baby
receives sufficient oxygen - and medications should be used as
appropriate to control the asthma and protect mother and child.
It is inadvisable to stop or reduce asthma medication solely because
of the pregnancy without careful supervision, as this can lead to
poorly controlled asthma, unnecessary ER visits, and poor outcome for
the baby and/or mother.
Most commonly-used asthma medications appear to be safe when used in
pregnancy; notable exceptions include the combination pills (Marax,
Tedral etc.) and those containing iodine (e.g. Theo-Organidin).
Many people are concerned in particular with the use of inhaled,
intranasal, and/or oral steroids but it has been my experience that
most doctors are quite willing to use these as needed, especially the
inhaled and intranasal steroids. It is my understanding that ephedrine
(alone or in combination drugs), and phenobarbital (an ingredient in
Tedral and other combination drugs) should be avoided.
There are choices in most classes of drugs, e.g., the bronchodilators,
and many doctors will elect to put their patients on those drugs with
the longest history of use in pregnant women - the assumption is that
the longer a drug has been in use, the likelier it is that any problems
would have become evident. For this reason, beclomethasone (Beclovent,
Vanceril) is the preferred inhaled corticosteroid. Cromolyn Sodium
(Nasalcrom, Intal) also appears to be safe for use in pregnancy.
In addition, if you need to use systemic steroids for a brief flareup,
old concerns over fetal abnormalities (cleft palate etc.) appear to
be less worrisome; I know of one case in which a woman used prednisone
for something other than asthma for several months while pregnant and
her baby had no problems.
Antibiotics may be used if needed; there are some such as tetracycline
which should be avoided but others (such as penicillin) appear to be
safe.
There is some anecdotal evidence from one contributer to the newsgroup
that Serevent, the longer-acting B2-agonist, might be related to several
cases of fetal abnormalities; I have not seen any official reports
supporting or denying this but it may be worth discussing with your
doctors if you use Serevent and are considering pregnancy.
Note: the above is a compilation of my own experiences as a pregnant
asthmatic, anecdotes from the newsgroup, and excerpts from The Asthma
Sourcebook and the National Asthma Education and Prevention Program
Expert Panel Report. It should in no way substitute for consultation
with qualified medical personnel.
======================================================================
2.0 What are the major classes of asthma medications?
------------------------------------------------------
There are seven major classes of asthma medications:
- steroidal anti-inflammatories,
- non-steroidal anti-inflammatories,
- beta-agonists,
- xanthines,
- anticholinergics,
- leukotriene receptor antagonists, and
- anti-allergics.
The first two categories of drug treat the underlying
inflammation of the lung. All steroidal anti-inflammatories
are glucocorticosteroids, which are entirely different from the
anabolic steroids that have become notorious for their abuse
by athletes. There are many different corticosteroids available
for the treatment of asthma, almost all available via inhaler
to reduce the amount of side effects (see section 2.3.6). The
non-steroidal anti-inflammatories currently available are
nedocromil sodium and cromolyn sodium, though cromolyn sodium
is perhaps more properly known as a mast cell stabilizer, since
it blocks both the release of histamine and inflammatory
mediators, which means that although it blocks the inflammatory
response, it cannot reverse inflammation once it has taken place.
For this reason, I have classed it as an anti-allergic since it
is mostly commonly taken for asthma that has a strong allergy
component.
The second two classes of asthma medications, beta-agonists and
xanthines, are both bronchodilators, meaning that they relax the
muscles lining the airways, allowing the airways to expand to
their normal size. Beta-agonists are chemically related to
adrenalin, but are specifically tailored to be more effective
on the muscles of the lung while having little effect on the
muscles in the heart. They are usually taken in inhaled form,
and all but one (salmeterol) are short-acting. Theophylline,
the major xanthine, is chemically related to caffeine, since
caffeine is also a xanthine derivative, and is present in tea.
Theophylline is taken orally, often in a sustained-action form
(see section 2.4). Because its therapeutic range is close to
its toxic range, asthmatics taking theophylline should have
their blood levels monitored to ensure that their blood
concentrations of theophylline lie within the therapeutic
range (see section 2.4.1). There are some asthmatics, however,
who cannot tolerate even very low doses of theophylline.
Anticholinergics, the fourth class of medication, work by
blocking the contraction of the underlying smooth muscle of
the bronchi. Although used to treat asthma in Canada, the
anticholinergic ipratropium bromide (Atrovent) has not approved
by the US Food and Drug Administration for the treatment of
asthma, but is used for the treatment of COPD.
(It is interesting to note, however, that in the April 1982
issue of The FDA Drug Bulletin, the FDA states that "the
FD&C Act does not, however, limit the manner in which a
physician may use an approved drug. Once a product has been
approved for marketing, a physician may prescribe it for uses
or in treatment regimens or patient populations that are not
included in a approved labeling." The FD&C Act is the Food,
Drug, and Cosmetic Act.)
The newest class of asthma medications is leukotriene receptor
antagonists. My information as to how they work is sketchy,
but as I understand it, the leukotriene receptor starts off the
inflammator response of the immune system when it detects an
allergen, so presumably an antagonist would block the receptor
from responding to the presence of an allergen. Zeneca
Pharmaceuticals has just now announced that its new leukotriene
receptor antagonist, zafirlukast (Accolate), has been approved
by the FDA (the US Food and Drug Administration) and will be
available in November of 1996. Abbott Laboratories now produces
a second drug in this class: zileuton (Zyflo).
The last class, the anti-allergics, has been included because
the two anti-allergic drugs, cromolyn sodium and ketotifen, are
commonly taken for the prevention of allergic asthma. Cromolyn
sodium is a mast cell stabilizer -- it blocks the release of
histamine from mast cells, which acts to prevent asthma flares
since histamine is a very strong bronchoconstrictor. However,
it isn't considered an antihistamine because it cannot prevent
the effects of histamine once the histamine has been released
from the cell. Similarly, it blocks the release of inflammatory
mediators from the mast cell, and so prevents the inflammatory
response, although it cannot reverse inflammation once the
mediators have been released. Ketotifen fumarate (Zaditen),
a non-sedating antihistamine used mostly for the treatment of
pediatric allergic asthma, is not currently available in the
United States.
2.1 What are the names of the various asthma medications?
----------------------------------------------------------
For a complete listing of asthma medications, please see the
alt.support.asthma FAQ: Asthma Medications. Allergy medi-
cations are listed in the alt.support.asthma FAQ: Allergy
Medications. They are posted monthly as companions to this
general information FAQ.
2.1.1 Are salbutamol and albuterol the same drug?
--------------------------------------------------
Ventolin is the brand name of salbutamol, which is the WHO
(World Health Organization) recommended name for the medication.
Unfortunately, in the US this same drug is called albuterol,
leading to endless confusion. In fact, it's one of the few
drugs in which the brand name stays the same from country
to country, while the chemical name changes! Ventolin is made
in the U.S. by Allen & Hanburys, and Proventil is the same drug
manufactured by Schering. You can also get this drug in
a sustained-action tablet, called either Repetabs (by Schering,
again) or Volmax (Muro).
2.1.2 Can albuterol be taken while taking salmeterol?
------------------------------------------------------
Yes. Quoting from the Product Information Sheet that comes
with the Serevent (salmeterol) inhaler, manufactured by
Allen & Hanburys:
"Serevent Inhalation Aerosol should not be used more frequently
than twice daily (morning and evening) at the recommend dose.
When prescribing Serevent Inhalation Aerosol, patients must be
provided with a short-acting, inhaled beta2-agonist
(e.g., albuterol) for treatment of symptoms that occur despite
regular twice-daily (morning and evening) use of Serevent."
"When patients begin treatment with Serevent Inhalation Aerosol,
those who have been taking short-acting, inhaled beta2-agonists
on a regular daily basis should be advised to discontinue their
regular daily-dosing regimen and should be clearly instructed to
use short-acting, inhaled beta2-agonists only for symptomatic
relief if they develop asthma symptoms while taking Serevent
Inhalation Aerosol."
"The safety of concomitant use of more than eight inhalations per
day of short-acting beta2-agonists with Serevent Inhalation
Aerosol has not been established."
So the above quotes seem to imply that it is okay for asthmatics
taking Serevent regularly to also use Ventolin (albuterol) as
needed, provided one doesn't need it too often.
2.2 Are some asthma drugs banned in athletic competitions?
-----------------------------------------------------------
The determination of whether a drug or substance is banned or
allowed in amateur athletic competitions is not based on whether
it is medically necessary. Rather, such a determination is based
on whether the substance in question can be performance-enhancing
and offer an unfair competitive advantage. There are several
organizations that make this determination and an athlete on an
asthmatic drug should check with his coaches, physician, and
appropriate athletic authority. Different athletic organizations
may differ on what is banned or allowed. For example, the
United States Olympic Committee (USOC) follows International
Olympic Committee guidelines for testing at Olympic events. Many
amateur athletic organizations (termed National Governing Bodies)
adopt USOC guidelines for drug testing at their events. In
contrast, the NCAA has less stringent guidelines for certain
substances used by asthmatics in during competitions. Further
complicating an athlete's understanding of the situation, some
substances that are banned in tablet form are allowed in inhaled
form.
As an example, the USOC allows inhaled forms of the beta-2 agonist
albuterol with written notification by a treating physician but
bans tablet forms of albuterol. Certain other beta-adrenergic
agonists (e.g. ephedrine, bitolterol, metaproterenol) are banned
by the USOC. An athlete who participates in an amateur athletic
event where drug testing may occur should check with his or her
coaches and physicians regarding the allowed vs. banned status of
any substance while competing. The United States Olympic
Committee Drug Hotline, (800) 233-0393, or NCAA, (800) 546-0441,
may provide information to specific questions on drugs, and
educational materials in this regard. An asthmatic should also
not assume that an over-the-counter (OTC) status of any drug
implies its allowed status in athletic competitions; many OTC
agents (e.g. combination decongestant-bronchodilators containing
ephedrine) or herbal preparations bought in food stores
(e.g. Ma Huang) contain stimulants useful for asthma but banned
in certain athletic competition settings.
Contributed by: Lyn Frumkin, M.D., Ph.D. lrfrum@u.washington.edu
2.3 What kinds of inhalers are there?
--------------------------------------
aerosol inhalers:
----------------
MDI - metered-dose inhaler, consisting of an aerosol unit
and plastic mouthpiece. This is currently the most
common type of inhaler, and is widely available.
autohaler - MDI made by 3M which is activated by one's breath,
and doesn't need the breath-hand coordination that
a regular MDI does. Available in U.S., UK, and NZ.
integra - MDI with compact spacer device. Available in UK.
respihaler - aerosol inhaler for Decadron. I have no idea how
this differs from the usual MDI. Available in the
U.S.
syncroner - MDI with elongated mouthpiece, used as training device
to see if medication is being inhaled properly.
Available in Canada and UK.
dry powder inhalers:
-------------------
accuhaler - dry powder inhaler for use with Serevent. It contains
a foil strip with 60 blisters, each containing one dose
of the drug. Pressing the lever punctures the blister,
allowing the drug to be inhaled through the mouthpiece.
Available in the UK.
diskhaler - dry powder inhaler. The drug is kept in a series of
little pouches on a disk; the diskhaler punctures
the pouch and drug is inhaled through the mouthpiece.
Currently available in Canada, South Africa, and UK,
not in U.S.
insufflator - dry powder nasal inhaler used with Rynacrom
cartridges. Each cartridge contains one dose;
the inhaler opens the cartridge, allowing the
powder to be blown into the nose by squeezing
the bulb. Available in Canada.
rotahaler - dry powder inhaler used with Rotacaps capsules.
Each capsule contains one dose; the inhaler opens
the capsule such that the powder may be inhaled
through the mouthpiece. Available in the U.S.,
Canada, and UK for Ventolin. In Canada, Beclovent
Rotacaps are also available, as are Becotide
Rotacaps in the UK.
spinhaler - dry powder inhaler used with Intal capsules for
spinhaler. Each capsule contains one dose; the
inhaler opens the capsule such that the powder
may be inhaled through the mouthpiece. Available
in Canada, UK, and the Netherlands. No longer
manufactured in the U.S.
turbuhaler - dry powder inhaler. The drug is in form of a pellet;
when body of inhaler is rotated, prescribed amount of
drug is ground off this pellet. The powder is then
inhaled through a fluted aperture on top. Available
in Australia, Canada, Denmark, Switzerland, and
the UK (spelled 'turbohaler' in the UK).
2.3.1 Do inhaler propellants bother some asthmatics?
-----------------------------------------------------
Some asthmatics find the dry powder inhalers more effective than
their MDI (aerosol) counterparts. It is suspected that the
aerosol or propellant in the MDI may act as an irritant to some
asthmatics, as in the following article:
J.R.W. Wilkinson et al., Paradoxical bronchoconstriction in
asthmatic patients after salmeterol by metered dose inhaler,
British Medical Journal 305 (1992) 931. The first sentence
in the conclusion is: "Bronchoconstriction after both
salmeterol and placebo by metered dose inhaler but not after
salmeterol by diskhaler suggests that the irritant is not
the salmeterol itself." . . . "The similarity in characteristics
of bronchoconstriction after beclomethasone by metered dose
inhalers implicates one or both chlorofluorocarbons . . . as
the irritant. That salbutamol caused no bronchoconstriction was
attributed to its faster onset of action opposing any
bronchoconstrictor effects of the propellants."
** However, according to the 1994 Physicians' Desk Reference,
Intal Spinhaler capsules are "contraindicated in those
patients who have shown hypersensitivity to . . . lactose."
So asthmatics who are lactose-intolerant may not have this
form of cromolyn sodium as an option.
2.3.2 What is a spacer? What is a holding chamber?
----------------------------------------------------
Metered dose inhalers (MDIs) for asthma medications typically
consist of a metal aerosol canister (containing the medication and
a propellant) in a plastic sleeve with a mouthpiece. The patient
inhales one or more metered doses of a medication through the
mouthpiece. Most people find it difficult (at least initially) to
time the spraying of an MDI and the inhalation of the medicine:
the patient must exhale fully and inhale and release the metered
dose just at the beginning of the inhalation so as to draw the
medication as fully and deeply into the lungs as possible.
All too often the puffs are mis-timed and only make it part of the
way into the airways, and some of the medication is invariably
deposited into the mouth and on the back of the throat instead of
into their lungs. In addition to being less effective, this can
lead to other side effects (e.g., for inhaled steroids, an
increased potential for thrush, an oral fungal infection described
in section 2.3.3).
Several devices have become available that address these
difficulties to varying degrees. The devices are generally
referred to as "spacers" since they place additional space between
the patient and the MDI. The medication is sprayed into the spacer
instead of the mouth. As the patient inhales, the column of
medication passes through the mouth and throat relatively quickly,
leaving little opportunity for the medication to be deposited in
the mouth or throat. This is a more efficient means of delivering
the medication to the airways where it's most needed.
The simplest kind of spacer is basically a tube. The patient
sprays the medication in one end of the tube and inhales it out
the other end. Azmacort has a simple spacer attached to it. A
cardboard tube from the core of a roll of bathroom tissue can be
used as a spacer (as long as it's clean, lint-free and germ-free).
While a simple spacer reduces the amount of medication that gets
deposited in the mouth and throat, it still requires you to
carefully time your inhalation with the discharge of the
medication to minimize the amount of the medication that escapes
from the spacer.
A "holding chamber" is a more sophisticated device. It is a sealed
chamber (once the inhaler is inserted) that traps and holds the
medication, allowing the patient to spray the medication into the
chamber and take a few seconds to inhale the medication. Since
the medication is temporarily suspended in the holding chamber,
the timing of the inhalation is not nearly as critical as with
simple spacers or no spacer. AeroChamber is a brand of holding
chamber. It's a plastic tube with a mouthpiece on one end and a
place to insert the MDI on the other. The mouthpiece has a
one-way valve built in that temporarily contains the sprayed
medication, and also allows the patient to exhale without
displacing the medication in the chamber (as without a spacer, the
patient should exhale as completely as possible before taking in
any medication, so that the medication can be inhaled as deeply as
possible).
In addition to improving the timing of the inhalation, a holding
chamber makes it possible to take in the medication more slowly
than is possible without a spacer or with a simple spacer. This
is important for the symptomatic patient, since rapid inhalation
of the medication is more likely to trigger coughing and cause the
patient to lose the medication before it has had a chance to be
absorbed.
Some spacers are clear so that you can see the puff of medicine,
and so that you can see when the medication is building up on the
inside, indicating that the spacer needs cleaning.
Spacers and holding chambers need periodic cleaning; clean
carefully, following the manufacturer's instructions so as not to
damage any delicate internal parts or allow molds or other
contaminants to be introduced.
There are special holding chambers for younger children. There's
a pediatric Aerochamber that has a mask built in; the child
breathes normally for a few seconds with the mask held over
his/her mouth and nose. This is typically used when a nebulizer
is not available or not required, and for medications that are not
available in a nebulized form, such as Beclovent or Vanceril.
There is also a device for children (and for people that have
trouble holding their breath) called an InspirEase. It's kind
of like a plastic bellows or balloon with a plastic mouthpiece.
The patient inflates it, the medicine is sprayed into it, and the
patient inhales, holds his/her breath for the count of 5 (or
whatever the doctor recommends), exhales into the device, and then
repeats. Some patients are instructed to breath slowly in and out
several times instead of holding their breath. The InspirEase
really helpful for younger children who yet aware of the
difference between breathing in and breathing out or don't yet
know how to hold their breath or breathe evenly and slowly. It
gives them immediate physical feedback, and it also has a whistle
built in to tell them when they're breathing too fast (although
they seem to like making it whistle, so it's positive
reinforcement for something that they shouldn't be doing). As the
child grows, the Inspirease becomes less effective, since it has a
limited capacity, although I've been told that it is available in
different capacities.
Knowing the difference between a simple spacer and a holding
chamber can help you use each in its proper way. If you use both a
holding chamber *and* a simple spacer (e.g., a holding chamber for
your Ventolin and the simple spacer attached to your Azmacort),
you need to remember which you're using and adjust your style
accordingly.
Spacers and holding chambers are sometimes provided by some HMOs
and covered by some insurers.
Contributed by: Mark Feblowitz mfeblowitz@GTE.com
[Maintainer's note: Some spacers seem to be prescription only,
while others are not. Whether you need a prescription also
seems to vary from state to state in the US. When in doubt,
ask. As to why you would need a prescription (i.e. how
could you abuse this simple plastic tube?), the nurses at
National Jewish were as puzzled as I was.]
2.3.3 What is "thrush mouth" and how can I avoid it?
-----------------------------------------------------
Thrush, or thrush mouth, is the popular term for a yeast
infection (candida albicans) in the back of throat. The major
symptom of thrush is a white film located at the back of the
throat and tonsil area. It is usually cured by the use of an
antifungal mouthwash.
Thrush is a very common side effect of taking inhaled
corticosteroids, since steroids alter the local bacteria and
fungal population of the mouth, enhancing fungal growth. The
way to avoid this complication is to ensure that the back of
the throat doesn't remain coated with corticosteroid after use
of the inhaler, either by using a spacer or by rinsing the mouth
very thoroughly afterwards. Unfortunately, some people still
get it even when they are very thorough about rinsing.
2.3.4 Is Fisons still making the Intal Spinhaler?
--------------------------------------------------
In the US, Fisons is no longer manufacturing either the
Intal Spinhaler (a dry powder inhaler for cromolyn sodium)
or the capsules for it. However, the Spinhaler and capsules
are still available in Canada and the United Kingdom. For
further information, Fisons Corporation's number in the US
for Rx Customer Service is (800) 334-6433.
2.3.5 What's the difference between Spinhalers and Rotahalers?
---------------------------------------------------------------
[Maintainer's note: the Rotahaler is a dry powder inhaler
for Ventolin (albuterol), manufactured by Allen & Hanburys,
while the Spinhaler is a dry powder inhaler for Intal
(cromolyn sodium), manufactured by Fisons Corporation. ]
The Rotahaler and the Spinhaler are very different animals.
The Rotahaler is a pussycat, the Spinhaler a ferocious lion.
The Rotahaler is a two-part mouthpiece that you snap apart,
put a capsule in, twist, and inhale. When you twist the device,
the capsule breaks open. When you inhale, the medicine lands
in your lungs.
The Spinhaler is a three-piece device: a mouthpiece, a tiny
fan, and a cap to cover the fan. You open it, put the capsule
in a space on the fan, close it, push down then up on the cap
(this breaks the capsule) and then tilt your head back, put
the mouthpiece in your mouth, and inhale. The fan throws the
medicine into the back of your throat. Then you gag.
I don't like the propellants in MDIs, so I was highly motivated
to get a Spinhaler. It took me a month to get my drugstore to
find it, and now I must admit I'm disappointed. I tried using
an Intal capsule in the Ventolin Rotahaler, since that device
works so well, but the medicine seems to be of the wrong
consistency, and the capsule is too large for the space it
should go into.
Another difference: The Spinhaler comes in a little container
like a medicine bottle, but the lid doesn't stay on very well in
a purse. The Rotahaler comes in a little plastic case sort of
like a compact and stays shut (i.e. clean) in a purse, backpack,
or jeans pocket.
Contributed by: Paula Ford pxf3@psuvm.psu.edu
2.3.6 Why are so many asthma drugs taken via inhaler?
------------------------------------------------------
Medications taken orally almost always have a much higher
systemic concentration (concentration in your entire body)
than inhaled medications. So if the side effects are due
to systemic concentrations, then an inhaled drug is less
likely to have these side effects, or may have them much
less severely.
The idea behind an inhaler is that the full dose is delivered to
the lungs, where it is immediately absorbed by the lung tissue,
and starts to take effect locally. Excess drug may be absorbed
by the bloodstream and delivered to the rest of your body, but
this amount tends to be minimal. So your lungs receive an
immediate, high concentration of the drug, and the rest of your
body receives very little.
If you take the drug orally in tablet or capsule form, then you
need a much higher dose. The reason is that for the same amount
of drug to reach the lungs through the bloodstream, you need the
same concentration of drug in the rest of your body. For example,
most people take one or two puffs of albuterol (Ventolin or
Proventil) every four to six hours, and each puff is 90 micrograms
of albuterol. The usual dosage of Ventolin in tablets is 2-4
milligrams three or four times a day, which is something like 200
times the amount inhaled.
However, one advantage that tablets have is that the medication
may be available in a time-release format. So for a short-acting
medication like albuterol, the inhaled version might need to be
taken every four to six hours, while a extended-release tablet
such as Volmax would need to be taken only every twelve hours.
2.3.7 How can I tell when my MDI is empty?
-------------------------------------------
The float test (in which you take the MDI canister out of the
mouthpiece and place it in a container of water to see if it
sinks) is no longer the recommended way to determine whether
your MDI (metered dose inhaler) is empty. Glaxo, the
manufacturer of Ventolin and Beclovent, claims that the float
test is inaccurate, and recommends that doses be counted instead.
Other manufacturers agree: the triamcinolone acetonide (Azmacort)
package insert recommends dose counting also and the cromolyn
sodium (Intal) inhaler package insert states that the metal
cylinder should never be immersed in water. The number of doses
per canister should be clearly written on the canister label.
One variation of dose counting, for medications that are taken
regularly, is to calculate the date on which the medication will
be used up, and discard the old canister for a new one on that date.
+ There is also a gadget called The Doser. It fits on top of any MDI,
and keeps track of how many doses you've dispensed from the inhaler.
It provides daily totals for the past 30 days, and is useful if
(like me) you tend to forget whether you've taken your maintenance
inhalers already! See http://www.doser.com for more information.
The Doser is over the counter, but the units can be hard to locate -
if a drugstore can get them at all, the pharmacist usually has to
special order them.
2.3.8 Are my aerosol inhalers going to disappear?
--------------------------------------------------
As you may know, CFC (chlorofluorocarbon) chemicals, which are used as
propellants in aerosol products including asthma inhalers (MDIs), damage
the ozone layer. As a result, there has been a worldwide ban on the
production of these chemicals for all but essential uses.
Products which relied on CFCs, such as air conditioning units,
refrigerators, and most aerosol products, have been modified to use
alternative chemicals which do not damage the ozone layer. Due to their
nature, however, metered dose inhalers have been granted an "essential
use" exemption to the worldwide ban, which grants the manufacturers an
extra few years to develop alternatives.
Since the inactive ingredients (i.e., everything but the drug itself)
must be changed, it's not as simple as using a different chemical for the
propellant - the new device must go through much the same approval
process as the original inhaler did, to ensure that the same dosage is
delivered to the patient, that there are no side effects, that patients
tolerate the new formulation well, etc.
The FDA has already approved one new non-CFC inhaler, Proventil HFA
(albuterol), which uses hydrofluoralkane instead of CFC propellants.
Other non-CFC devices are currently in the works. It is expected that
future non-CFC inhalers may be reviewed and approved more quickly than
the earlier ones.
CFC-based MDIs will continue to be available for some time. Proposed
guidelines for final phaseout include that there be at least 3 multi-use
(see below) non-CFC devices available in a drug class (i.e.,
bronchodilators, corticosteroids), providing at least 2 different drugs,
before all CFC inhalers in that class are banned. As an example,
CFC-based bronchodilators would be permitted as long as Proventil HFA is
the only alternative; if Ventolin (also albuterol) and Alupent
(metaproterenol) had non-CFC versions, then all CFC formulations might be
banned.
The term "multi-use" refers both to aerosol inhalers and multi-use
dry-powder inhalers such as the diskhaler. It does not include
single-use dry-powder inhalers such as the rotahaler, which requires
insertion of a new capsule of medication with each use.
2.4 What kinds of tablets are there?
-------------------------------------
CR - controlled release. This means that the drug has a
constant rate of release.
DR - delayed release. This generally refers to enteric-
coated tablets which are designed to release the drug
in the intestine where the pH is in the alkaline range.
ER - extended release. Dosage forms which are designed to
release the drug over an extended period of time, such
as implants which release the drug over a period of
months or years.
SA - sustained action. Used interchangeably with CR
(above), except that SA usually refers to the
pharmacologic action while CR refers to the drug
release process.
TD - time delayed. This is slightly different from DR in
that the drug release is designed to occur after a
certain period of time, such as pellets coated to a
certain thickness, multi-layered tablets, tablets
within a capsule, or double-compressed tablets.
Contributed by: Susan Graham sgraham@hpb.hwc.ca
2.4.1 Why do I need a blood test when taking theophylline?
-----------------------------------------------------------
Theophylline is commonly used as a third-line agent in the
management of asthma, after beta-agonists and anti-inflammatories.
Unfortunately, its therapeutic level is quite close to its toxic
level. This means that the dose that the asthmatic needs to get
the full benefit of the drug is not very much lower than the dose
which causes side effects which range from unpleasant to
dangerous. This would not be such a problem if there weren't
such large variations in the rate at which people metabolize
theophylline. Apparently, if a group of people are given
the same dose of theophylline, the concentration of the
drug in their bloodstreams may vary by up to a factor of
seven. Therefore, the best way to monitor that the asthmatic
is receiving the optimal amount of theophylline is to take
a blood level concentration.
2.4.2 Why are combination pills not commonly prescribed?
---------------------------------------------------------
The combination drugs such as Tedral and Marax commonly
contain theophylline, ephedrine, and some form of sedative
such as phenobarbital. These combination pills are no longer
commonly prescribed because the amount of theophylline in
the pill cannot be varied with respect to the other drugs.
Since there is great variation in the rate at which an
individual metabolizes theophylline, it is now considered
better to take theophylline separately, for better adjustment
of theophylline levels. In fact, Tedral is no longer
manufactured by Parke-Davis in the U.S.
Also, ephedrine is no longer considered the bronchodilator
of choice. From Drs. Haas, _The Essential Asthma Book_,
"ephedrine initiates the release of catecholamines -- including
adrenaline -- that are already stored in the body. This is
its biggest drawback. Its effects depend on the availability
of catecholamine in the body at the time it is given, and
these concentrations vary." Since much better bronchodilators
are now available, ephedrine is no longer commonly prescribed.
2.5 What is a nebulizer?
-------------------------
A nebulizer is a device that uses pressurized air to turn a
liquid medication into a fine mist for inhalation. If you've
ever received emergency treatment for asthma, they've probably
used a nebulizer on you.
The term nebulizer is often used to describe both the pump
that pressurizes the air, and the part that holds and
"nebulizes" the medication. There are hand-held nebulizer
units and ones with masks that you strap onto your face.
The pressurized air typically comes from a portable pump unit
that internally consists of a motor-driven air pump that
resembles the fancier types of aquarium pumps. It forces air
through a plastic tube into the plastic nebulizer unit. Inside,
the nebulizer unit acts much like a perfume atomizer, creating
a fine mist that is directed either through a tube that you
inhale through or a mask that directs the mist into your nose
and mouth.
Since the nebulizer takes a few minutes to deliver the medication,
you inhale it over a longer period of time than if you were using
an inhaler. This can really help, especially if your passages are
not fully open and you're taking a bronchodilator. As you breathe
the medication, your lungs can gradually accept more and more of
the medication. In addition to the medication, many people find
the accompanying mist (typically a sterile saline solution) to be
soothing.
For very young children, the nebulizer is the only practical
means of administering inhaled medications. Older children and
adults have the options of using inhalers and a variety of
spacers to make the timing a bit easier. The doctor overseeing
the treatment decides which is the most effective/appropriate
delivery mechanism.
At least in Massachusetts, the nebulizer pump unit, the
hand-held nebulizers, the medications, and the sterile saline
inhalation solution are all prescription items. Replacement
parts for the pumps are not available to the general public
(if there are sources, I'd like to hear about them).
The portable nebulizer pump units cost little ($100-$300)
relative to the cost of an emergency room visit, so some health
plans / insurers provide them to patients for times when an
asthma episode is "manageable but not dangerous." This seems to
be a trend in the management of pediatric asthma.
Our family has been able to successfully avoid a few trips to
the ER, and have even been able to head off some more severe
allergic asthma episodes with early intervention. After a few
rather gruesome visits to the Mass. General Hospital's waiting
room on a Saturday night, we welcome opportunity to treat our
children at home, when it's safe. We tend to go in to the doctor
or ER for the more severe episodes or those that don't respond
well enough to early intervention.
Contributed by: Mark Feblowitz mfeblowitz@GTE.com
2.6 What medications should asthmatics be careful about taking?
----------------------------------------------------------------
Aspirin can trigger an asthma attack in approximately one in
five asthmatics. This is especially common in those asthmatics
who also have nasal polyps. As acetominophen (Tylenol), also
known as paracetamol overseas, doesn't have this effect, it may
be used as an alternative for anyone who suspects that they might
have aspirin sensitivity.
Cough medicines should also be treated with caution. In general,
suppressing a productive cough (one which is bringing up mucus)
is not a good idea, since the mucus can obstruct the airways
and also irritate them further. Also, in _Asthma: Stop
Suffering, Start Living_, the authors caution that "prescription
cough suppressants (including those with codeine) are potentially
dangerous for asthmatics. They may make you sleepy and reduce
your breathing effort. They may also dry out your secretions,
making mucus harder to raise."
Antihistamines, however, should not pose a problem for most
asthmatics, in spite of many warning labels. In _Children with
Asthma_, Dr. Plaut states, "Most asthma experts see no problems
with using antihistamines between or during asthmatics . . .
Theoretically these drugs might dry up the mucus in the
windpipes, thus making it harder to cough it up, but this has
never been proved."
Asthmatics taking theophylline should be careful when taking any
of the following medications: the ulcer medications cimetidine
(Tagamet) and troleandomycin (TAO), beta-blocker drugs such as
propranolol, and the antibiotics erythromycin and ciprofloxacin.
These medications may increase the concentration of theophylline
in the bloodstream, possibly even to the toxic level (see
section 2.4.1). People taking theophylline should be alert for
signs of possible toxicity such as rapid or irregular heartrate,
nervousness, or nausea, when taking these medications. In fact,
asthmatics taking theophylline should check with their physician
before taking any OTC medication, as the list of drugs, including
antihistamines, which affect theophylline levels is almost
endless.
Beta-blockers, usually taken for hypertension, can pose problems
even for those asthmatics not taking theophylline. Beta-blockers
work by blocking the hormone adrenalin, but as adrenalin and
other adrenergic drugs help keep airways dilated, the use of
beta-blockers may aggravate asthma symptoms.
2.6.1 What about corticosteroids and chicken pox?
--------------------------------------------------
According to the pamphlet "Advice from your Allergist", published
by the American College of Allergy & Immunology, children taking
oral or injected corticosteroids may be at increased risk of
complications from chicken pox. Such children should avoid
exposure to chicken pox -- if the child has been exposed, their
physician should be notified. However, the child's medications
shouldn't be changed without advice from their physician, since
corticosteroid therapy should not be stopped abruptly.
Children taking inhaled corticosteroids are not at this increased
risk, according to the pamphlet, since the system concentrations
of the medication are so small.
======================================================================
3.0 What resources are there for asthmatics?
---------------------------------------------
Please see the alt.support.asthma Reading/Resource List. It
is maintained by Lynn Short <lfshort@europa.com>, and is
posted periodically to alt.support.asthma, alt.med.allergy,
sci.med, and misc.kids. I highly recommend it!
I also strongly recommend the following guidelines: the
"Global Initiative for Asthma", the "NHLBI Executive Summary:
Guidelines for the Diagnosis and Management of Asthma", and
the "Executive Summary: Management of Asthma during Pregnancy"
(full citations in References section). They may be ordered
in the U.S. by calling (301) 251-1222 and asking for publication
numbers 95-3659, 94-3042A, and 93-3279A, respectively. When I
ordered them, and asked that they be sent to a US address, there
was no charge.
Another set of guidelines which has been recommended to me but
which I haven't seen myself yet is "NAEPP. Nurses: Partners
in Asthma Care", publication number 95-3308, which I assume is
also available at the number given above.
The newsgroup misc.kids also has an allergy and asthma FAQ,
which is available either by following the instructions
posted on misc.kids.info, or by accessing the World Wide Web,
<URL: http://www.cs.unc.edu/~kupstas/FAQ.html>.
In addition, I maintain an Asthma and Allergy WWW Resources Page,
<URL: http://www.cco.caltech.edu/~wrean/resources.html>, and
two FAQs on allergies. For information on how to access these
allergy FAQs, please see section 3.1.
3.1 Where can I get the latest copy of the FAQs?
-------------------------------------------------
The two asthma FAQs I maintain,
alt.support.asthma FAQ: Asthma -- General Information
alt.support.asthma FAQ: Asthma Medications
are posted once a month, on or about the 17th, to the following
newsgroups: alt.support.asthma, alt.med.allergy, sci.med,
alt.answers, sci.answers, and news.answers.
If these FAQs have already expired at your site, you can get
them by sending mail to mail-server@rtfm.mit.edu, with a blank
subject line, and with one or more of the following commands
in the message:
send usenet/news.answers/medicine/asthma/general-info
send usenet/news.answers/medicine/asthma/medications
Alternatively, if you're really in a hurry, you can get them via
anonymous ftp from rtfm.mit.edu, with the path names:
/pub/usenet/news.answers/medicine/asthma/general-info
/pub/usenet/news.answers/medicine/asthma/medications
The general information FAQ is also available in html format on
the World Wide Web, at
<URL: http://www.radix.net/~mwg/asthma-gen.html>; a plaintext
version of the FAQ is at http://www.radix.net/~mwg/asthma-gen.txt.
Of the two allergy FAQs I maintain,
alt.support.asthma FAQ: Allergies -- General Information
alt.support.asthma FAQ: Allergy Medications
the first is still under construction. The second is posted
monthly to the following newsgroups: alt.support.asthma,
alt.med.allergy, sci.med, alt.answers, sci.answers, and news.answers.
If the allergy medication FAQ has already expired at your site, you
can get it by sending mail to mail-server@rtfm.mit.edu, with a blank
subject line, and with the following command in the message:
send usenet/news.answers/medicine/allergy/medications
Alternatively, if you're really in a hurry, you can get it via
anonymous ftp from rtfm.mit.edu, with the path name:
/pub/usenet/news.answers/medicine/allergy/medications
3.2 What is an FAQ, anyway? What is a Usenet newsgroup?
---------------------------------------------------------
The term FAQ is an acronym which stands for Frequently Asked
Questions. Often the term is also used for any document, such
as this one, which attempts to answer questions which are
frequently posted to a specific Usenet newsgroup. For example,
this is one of the three alt.support.asthma FAQs which attempt
to answer questions frequently posted to the newsgroup
alt.support.asthma.
A newsgroup is a world-wide electronic forum of discussion which
generally takes place over the Internet, each newsgroup having
its own topic of discussion. For more information about FAQs and
newsgroups in general, I recommend any of the periodical postings
in the newsgroup news.announce.newusers, particularly
"FAQs about FAQs" and "What is Usenet?" These last two may also
be accessed by sending mail to mail-server@rtfm.mit.edu, with a
blank subject line, and with one or both of the following commands
in the message:
send usenet/news.answers/faqs/about-faqs
send usenet/news.answers/usenet/what-is/part1
Alternatively, if you're really in a hurry, you can get them via
anonymous ftp from rtfm.mit.edu, with the path names:
/pub/usenet/news.answers/faqs/about-faqs
/pub/usenet/news.answers/usenet/what-is/part1
+3.3 How about some other WWW links?
---------------------------------------------------------
The original Asthma Resources page that Pat maintained is temporarily
unavailable. In the meantime, I'm compiling a list of a few
sites whose URLs I have handy. As with any website, these are
not intended to substitute for competent medical advice, nor
do I vouch for the currency or accuracy of information on these
sites.
http://asthma.about.com
http://www.virtualdrugstore.com
http://www.cs.unc.edu/~kupstas/FAQ.html
http://nationaljewish.org
http://www.vh.org/Providers/ClinGuide/AsthmaIM/staging/chronic/classif.html
http://www.pslgroup.com
http://www.srs.org.uk
http://www.gpiag-asthma.org/asthma/GPIAG/welcome.htm
http://www.nhlbi.nih.gov/index.htm
http://www.nhlbisupport.com/asthma/index.html
======================================================================
List of Contributors:
---------------------
Kevin Ball kb036@seqeb.gov.au
Betty Bridges bcb56@ix.netcom.com
Mark Delany markd@bushwire.apana.org.au
Mark Feblowitz mfeblowitz@GTE.com
Bill Ellis Fleenor efleenor@pacbell.net
Paula Ford pxf3@psuvm.psu.edu
Lyn Frumkin, M.D., Ph.D. lrfrum@u.washington.edu
Joe Gems jgems@cais.com
Susan Graham sgraham@hpb.hwc.ca
Gwenith Jones gaj5m@virginia.edu
Philip D. Mayo, M.D., FCCP cn1435@coastalnet.com
Judith B. Paquet, R.N. judyp@snip.net
======================================================================
References:
----------
The Physicians' Desk Reference is published annually by:
Medical Economics Data Production Company
Montvale, NJ 07645-1742
ISBN 1-56363-061-3
It is a compendium of official, FDA-approved prescription
drug labeling. The FDA is the U.S. Food and Drug Administration.
The Compendium of Pharmaceuticals and Specialties is published
annually by:
Canadian Pharmaceutical Association
Ottawa, Ontario, Canada K1G 3Y6
ISBN 0-919115-94-2
Robert Berkow, M.D., editor in chief, _The Merck Manual of Diagnosis
and Therapy_, 15th ed., (Merck & Co., Inc., USA) 1987.
ISBN 0911910-06-09
The Merck Manual provides an overview of the diagnosis and
therapy of the whole range of medical disorders that can occur
in infants, children, and adults. I am told that the 16th
edition is now available, with ISBN 0911910-16-6, and that
the 17th edition should be available sometime in 1997.
"Global Initiative for Asthma: Global strategy for Asthma Management
and Prevention. NHLBI/WHO Workshop Report. March 1993",
National Institutes of Health/NHLBI, Publication No. 95-3659,
January 1995.
These are often called the "GINA Guidelines".
National Asthma Education Program Expert Panel Report, "Executive
Summary: Guidelines for the Diagnosis and Management of Asthma",
U.S. Department of Health and Human Services, Public Health
Service, National Institutes of Health, Publication No. 94-3042A,
Reprinted July 1994.
Often called the "NHLBI Guidelines", this is a summary of the
current wisdom on asthma treatment and prevention for physicians.
I found it very readable.
The above report, written in 1991, has now been superseded by:
National Asthma Education and Prevention Program Expert Panel Report 2:
Guidelines for the Diagnosis and Management of Asthma (revised
6/18/97)
This report provides clinicians with recommendations for the
diagnosis and management of asthma. These recommendations are
organized into four components of therapy: measures of assessment
and monitoring, control of factors contributing to asthma severity,
pharmacologic therapy, and education for a partnership in asthma care.
The recommendations are an update of the 1991 Expert Panel Report.
The report can be accessed directly from
http://www.ama-assn.org/special/asthma/treatmnt
/guide/guidelin/guidelin.htm
Report of the Working Group on Asthma and Pregnancy, "Executive
Summary: Managment of Asthma during Pregnancy", National
Institutes of Health/NHLBI, Publication No. 93-3279A, March 1993.
The American College of Allergy & Immunology, (ACAI), publishes a
pamphlet titled "Advice from your Allergist." It may be
ordered from:
ACAI
85 West Algonquin Road, Suite 550
Arlington Heights, IL 60005
(708) 427-1200
+ Michael R. Freedman, Samuel J. Rosenberg, Cynthia L. Divino
Living Well With Asthma (Guilford Press, USA) 1998.
ISBN 1572303182 hardback, 1572300515 paperback
The authors are former associates of National Jewish
Medical and Research Center.
M. Eric Gershwin, M.D., and E.L. Klingelhofer, Ph.D., _Asthma:
Stop Suffering, Start Living_, 2nd ed., (Addison-Wesley, USA) 1986.
ISBN 0-201-60847-2
The first author is Chief of Allergy and Immunology, University
of California, Davis, Medical School. He is board-certified
in internal medicine, allergy, and clinical immunology.
Drs. Francois Haas and Sheila Sperber Haas, _The Essential Asthma
Book_, (Ballentine Books, USA) 1987.
ISBN 0-8041-0287-2
Dr. Francois Haas is the director of the Pulmonary Function
Laboratory at the Medical Center of the New York University
School of Medicine, and is on the faculty of the Department
of Physiology there.
Paul J. Hannaway, M.D. _The Asthma Self Help Book: how to live a
normal life in spite of your condition_, 2nd ed., (Prima
Publishing, USA) 1992.
ISBN 1-55958-166-2, 1-55958-434-3 paperback
The author is Assistant Clinical Professor of Tufts University
School of Medicine. The first edition of this book won an
American Medical Writers Association Award.
Glennon H. Paul, M.D. and Barbara A. Fafoglia, _All About Asthma
& How to Live with It: the complete guide to understanding and
controlling asthma_, (Sterling Publishing Co., NY, USA) 1988.
ISBN 0-8069-6808-7, 0-8069-6809-5 paperback
Dr. Paul is the medical director of respiratory therapy at
St. John's Hospital in Springfield, Illinois, and specializes
in allergy and respiratory diseases.
Thomas F. Plaut, _Children with Asthma -- A Manual for Parents_,
(Pedipress, Inc., Amherst, Massachusetts, USA) 2nd edition 1995.
ISBN 0-914625-03-9
Richard N. Podell, M.D. and William Proctor, _When Your Doctor Doesn't
Know Best: medical mistakes that even the best doctors make --
and how to protect yourself_, (Simon & Schuster, USA) 1995.
ISBN 0-671-87112-9
Nancy Sander, _A Parent's Guide to Asthma_, (Doubleday, USA) 1989.
ISBN 0-385-24478-9
The author is the founder of Mothers of Asthmatics.
Genell Subak-Sharpe, _Breathing Easy -- A Handbook for Asthmatics_,
(Doubleday, NY, USA) 1988.
ISBN 0-385-23440-6
This book was written in consultation with the National Jewish
Center for Immunology and Respiratory Medicine.
Allan M. Weinstein, M.D., _Asthma - The Complete Guide to Self-
Management of Asthma and Allergies for Patients and their
Families_, (Fawcett Crest, NY, USA) 1987.
ISBN 0-449-21562-8
The author is Assistant Clinical Professor of Medicine at
Georgetown University, and is a board-certified allergist who
practices in Washington, D.C.
Stuart H. Young, M.D. with Susan A. Shulman and Martin D. Shulman,
_The Asthma Handbook -- A Complete Guide for Patients and Their
Families_, (Bantam Books, USA) 1985.
ISBN 0-553-24797-2
Dr. Young is the Chief of Allergy Clinics in both the Department
of Medicine and Department of Pediatrics at the Mount Sinai
Medical Center. He is also a clinical assistant professor of
Medicine and a clinical associate professor of Pediatrics at the
Mount Sinai Medical School.
Francis V. Adams, MD, _The Asthma Sourcebook_ (Lowell House, Los Angeles
CA) 1996
ISBN 1-56565-471-471-4
Dr. Adams is an award-winning pulmonary specialist in the field of
asthma. He is currently Assistant Professor of Clinical Medicine at
New York University and Attending Physician at Bellevue Hospital in
New York.
The following citations were used in compiling the
Occupational Asthma section:
O'Neil, CE: Review: Mechanisms of Occupational Airways Diseases
Induced by Exposures to Organic and Inorganic Chemicals. Am j Med Sci
1990; 299(4) 265-275
Bernstein, DI: Respiratory Sensitization to Chemical Allergens.
Masters in Allergy Vol 1, (1) 17-21
Grammer, LC: Occupational Asthma. Immunology and Allergy Clinics
of North America Vol 13 (4) Nov 1993 769-783
Chan-Yeung, M: A Clinician's Approach to Determine the Diagnosis,
Prognosis, and Therapy of Occupational Asthma. Medical Clinics of
North America Vol 74 (3) May 1990 811-822
======================================================================
Disclaimer: I am not a physician; I am only a reasonably
well-informed asthmatic. This information is for
educational purposes only, and should be used only as
a supplement to, not a substitute for, professional
medical advice.
Copyright 1996 by Patricia Wrean, 1997-2000 by Marie Goldenberg. Permission is
given to freely copy or distribute this FAQ provided that it is
distributed in full without modification, and that such distribution is
not intended for profit.
User Contributions:
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