Treating strep - amoxicillin over penicillin

Pediatrics for Parents, June, 1993

For almost 40 years, penicillin has been the mainstay for treating strep throat. Many studies have examined how many doses per day and how many days of treatment are needed to eradicate the bacteria. Other studies have looked at the effectiveness of many of the newer antibiotics which have the advantage of fewer doses per day. But most of the newer antibiotics are more costly than penicillin.

Amoxicillin, a semi-synthetic penicillin, has many advantages over penicillin, and is the drug most frequently prescribed for treating ear infections. Doctors in Israel wondered why not use amoxicillin for the treatment of strep throats.

To evaluate its effectiveness, they enrolled 157 children with culture proven streptococcal pharyngitis in a study. Approximately half were treated with a standard course of penicillin, the other half received the standard total daily dose of amoxicillin once a day. (Amoxicillin is usually given three times a day.)

There were no differences in the response of the two groups. The resolution of the symptoms compared (fever, sore throat, malaise, and headache) was the same for both groups. Both groups had the same number of lost work or school days. There were no side effects reported in either group. Repeat throat cultures 14 days after the initiation of treatment were positive in six percent of those treated with penicillin and in none of the patients treated with amoxicillin.

Perhaps the traditional dominance of penicillin as the drug of choice for treating strep throat should be reevaluated. Once a day dosing of amoxicillin may be a better choice.

British Medical Journal. 5/1/93, pp. 1170-2.