Antibiotics are the main treatment for infections of the ear. Infections are generally either otitis media or otitis externa. Otitis refers to an infection or inflammation of the ear. Otitis media is infection of the middle ear, behind the typanic membrane or eardrum. Otitis externa is infection of the ear canal and is also known as swimmer's ear.
Medications for Otitis Media
There is some flexibility in the choice of antibiotics for otitis media. Preferably the drug will be active against three bacteria: Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis, according to "Harrison's Principles of Internal Medicine." Initial therapy is often the antibiotic amoxicillin. This drug inhibits the formation of the bacterial wall, so the bacteria are unable to be protected from the environment. In people with a penicillin allergy, a cephalosporin can be used. These drugs have the same mechanism as amoxicillin. If a person is allergic to both categories of drugs, then erythromycin may be a third-choice drug.
Medications for Otitis Externa
Unlike infection of the middle ear, infection of the ear canal and outer ear, or otitis externa, is more likely to be treated with topical antibiotics such as ear drops. The antibiotic should be effective against the bacteria Pseudomonas aeruginosa and Staphylococcus aureus. Examples include Cipro HC and Tobradex.
Medications for Resistant Infections
The bacteria that cause otitis externa tend to have many enzymes that make them resistant to antibiotics, so the first-choice topical antibiotics tend to be strong and target those bacteria specifically. Most cases of otitis media will respond to the types of antibiotics mentioned previously. If the ear infection does not respond, examples of drugs that can be used include amoxicillin plus clavulanate. The clavulanate inhibits enzymes that the bacteria use to break down amoxicillin.
References
- "Harrison's Principles of Internal Medicine"; Anthony S. Fauci; 2008
- "The Sanford Guide to Antimicrobial Therapy"; David N. Gilbert, Robert C. Moellering, George M. Eliopoulos and Henry F. Chambers; 2010
