Tonsillitis is an inflammation of the tonsils, and bacterial forms of the disease can be treated by a variety of antibiotics. Streptococcus, or strep, is the usual cause of bacterial tonsillitis, and penicillin is the most common antibiotic prescribed to treat it. Other tonsillitis antibiotics are prescribed in the case of penicillin allergy.
Penicillin, or the related drug amoxicillin, are the standard treatment for tonsillitis. The normal dose for adults is 500 milligrams, taken twice daily for seven to ten days. The dose for children varies by age. Allergic or other adverse reactions to penicillin and related drugs are fairly common, so if there is a history of either of these, an alternative antibiotic must be used.
Erythromycin is sometimes prescribed when the patient has had a previous reaction to a drug in the penicillin family. The dosing is the same as that of the penicillin drugs. There is some evidence that strep bacteria is becoming resistant to erythromycin, however, so other drug options are often considered first.
Azithromycin can also be used if patients have penicillin sensitivities. This drug is typically given in a pack of five 250 milligram pills. Two are taken the first day, and then one is taken each subsequent day until the pills are gone. Azithromycin has the advantage of not interacting with many other drugs, so it is often given to patients who take a lot of medications. Like erythromycin, some strains of strep bacteria are becoming resistant.
Streptococcus currently shows no resistance to doxycycline. The typical adult dose is 100 milligrams twice daily. This drug may stain the teeth of children, so it should only be considered if there are sensitivities to other antibiotics.
Cephalexin may be considered if there is an allergy or sensitivity to penicillin drugs, although about 20% of patients react to both. There is no evidence for strep resistance, and the typical dose is the same as the penicillin drugs. Cephalexin does not have many drug interactions and is generally well-tolerated, producing few side effects.
There are many tonsillitis antibiotics available, and most will destroy the most common cause of bacterial tonsillitis, streptococcus. Some drugs may not be effective, however, since strep is becoming resistant to them. This can happen when antibiotics are given when they are not needed, such as to treat a viral infection. It can also happen if patients stop taking the drug before all of their pills are gone.