Ear drops are a generic method for introducing both saline and antibiotic medications into the ear. The ear is an organ that is continually exposed to both the risk of infection as well as numerous other structural injuries, the most serious of which is a punctured ear drum.
The ear is divided for medical purposes into three parts—the outer ear, which includes the external cartilage and the canal leading into the areas inaccessible to the touch; the middle ear, a chamber that accesses the ear drum, the most important structure for unimpaired hearing; and the inner ear, which contains the small and intricate canals of the vestibular system, the device within the body that provides ongoing information to assist with balance and the ability of an athlete to track an object that is traveling through the air.
Ear drops are most often employed to counter the effects of ear infections that can arise from a number of external sources. One common source of ear infection is the blockage of the Eustachian tube, the passage from the middle ear to the throat, a drainage canal that carries away from the ear bacteria trapped by the mucus that is present with the tube. When a person swallows, the tube opens and the mucus is passed from the tube, into the throat, where the bacteria are ultimately carried away for destruction by stomach bile. The tube also assists in the regulation of air pressure between the ear and the mouth cavity. When the Eustachian tube becomes blocked, the trapped bacteria often multiply in the upper portion of the tube and the middle ear cavity. The resulting middle ear infection is known as otitis media.
Blockages of the Eustachian tube can result from an upper respiratory system infection, such as sinusitis (sinus passage infection), an allergic reaction, or the presence of smoke or other foreign particles. The otitis media that results will often cause both a temporary hearing loss and localized pain to the subject.
The second type of infection that may occurs in both the middle or inner ear is otitis externa, often referred to by the mechanism that most frequently creates the infection: swimmer's ear. This condition occurs where water enters the ear through the outer canal, becoming trapped along with companion bacteria within the middle ear. The infection created by the presence of bacteria develops on the surface of the skin of the ear canal. If not properly treated, swimmer's ear can also cause significant pain and a partial hearing loss.
Infections of the ear are most often treated through the administration of ear drops, where the active ingredient designed to counter the infection is delivered to the affected area in a fluid that is dropped into the ear canal. The fluid is designed to travel into the middle or inner ear, as may be required. In ideal circumstances, the ear drops will be administered by a second person, in order that the subject can place their head at an optimal angle for the antibiotic to enter the organ. Antibiotics can take many forms in the treatment of ear infections; various corticosteroids are sometimes employed to counter inflammation, and aminoglycosides, of which streptomycin is the best known. These chemicals interfere in the growth of bacteria so as to reverse their spread, ultimately killing these cells. The risk in the administration of some antibiotic formulations in the middle ear is that some antibiotics are toxic to the sensitive membranes of the inner ear, a consequence called ototoxicity. Ototoxicity most often arises where an antibiotic is directed at a middle ear infection, but due to the presence of an undetected perforated ear drum, the medication passes into a region for which it was not intended.
The other risk of antibiotic application to counter ear infections is the creation of a resistant strain of bacteria. This can occur when antibiotics do not kill the entire infection, and some of the bacteria survives and is then, resistant to various antibiotics.
Ear drops are also used to deliver nonmedicinal substances into the ear cavity to assist in the break up and removal of ear wax that has become impacted in the ear canal. Ear wax, known by its scientific name cerumen, is produced by the glands located in the skin of the outer ear, to provide the ear with lubrication, and to trap dirt and foreign particles that might otherwise enter the middle ear. When ear wax accumulates, it can impair the hearing of an individual. Various sterile solutions are employed to loosen impacted ear wax; many of these products contain glycerin or similar chemicals that act to soften the wax to permit it to be safely removed from the ear canal.
Ear infections are most common among children under the age of two years, a circumstance related to the fact that infants are not completely protected by their still developing immune system. Ear infections and ear wax conditions can affect persons of any age.