Urinary anti-infectives are medicines used to treat or prevent infections ofthe urinary tract--the passage through which urine flows from the kidneys outof the body.
Normally, no bacteria or other disease-causing organisms live in the bladder.Likewise, the urethra--the tube-like structure that carries urine from the bladder out of the body--usually has either no bacteria or not enough to causeproblems. But the bladder, urethra, and other parts of the urinary tract maybecome infected when disease-causing organisms invade from other body regions or from outside the body. Urinary anti-infectives are used to treat such infections or to prevent them in people who get them often.
Commonly used urinary anti-infectives include methenamine (Urex, Hiprex, Mandelamine), nalidixic acid (NegGram) and nitrofurantoin (Macrobid, Furatoin, and other brands). These medicines are available only with a physician's prescription and come in capsule, tablet, granule, and liquid forms.
People with certain medical conditions must take precautions because they mayhave problems if they take methenamine, nalidixic acid, nitrofurantoin.
For example, people with severe liver disease who take methenamine may have worsened symptoms of their disease. And people who are dehydrated or who havesevere kidney disease may be more likely to have side effects that affect thekidneys.
Some people feel drowsy, dizzy, or less alert than usual when using nalidixicacid. The medicine may also cause blurred vision or other vision changes. Because of these possible problems, anyone who takes nalidixic acid should notdrive, operate machinery, or do anything else that might be dangerous until they have found out how the drugs affect them.
Nalidixic acid may increase sensitivity to sunlight. Even brief exposure to sun can cause a severe sunburn or a rash.
Women who are breastfeeding should check with their physicians before using nitrofurantoin. It passes into breast milk and could cause problems in nursingbabies whose mothers take it. This is especially true of babies with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The medicine also should not begiven directly to babies up to 1 month of age.
Older people may be more likely to have side effects when taking nitrofurantoin, because they are more sensitive to the drug's effects.
There are some general precautions for all urinary anti-infectives. Symptomsshould improve within a few days of starting to take a urinary anti-infective. If they do not, or if they become worse, check with a physician right away.Patients who need to take this medicine for long periods should see their physicians regularly, so that the physician can check their progress.
Anyone who has had unusual reactions to urinary anti-infectives in the past should let his or her physician know before taking the drugs again. The physician should also be told about any allergies to foods, dyes, preservatives, orother substances.
People who take urinary anti-infectives should be aware that side effects arepossible. Anyone who has unusual symptoms while taking this type of medicineshould get in touch with his or her physician.
All the drugs that may interact with a urinary anti-infective are not listedhere. Be sure to check with a physician or pharmacist before combining a urinary anti-infective with any other prescription or nonprescription (over-the-counter) medicine.