Pharmacological and clinical study of bacampicillin in acute peritonsillitis--a comparison with ampicillin.

The pharmacological and clinical properties of bacampicillin in three dosage groups were studied in 66 hospitalized patients with unilateral acute peritonsillitis in a comparison with ampicillin. Bacampicillin is a new semisynthetic aminopenicillin which is rapidly converted to ampicillin but is better absorbed. Both drugs were given orally. The mean individual peak serum levels achieved with 200, 400, and 800 mg of bacampicillin in the first morning dose were 4.9, 6.8, and 11.9 mg/liter, respectively, with an almost linear dose response. The peak level of 800 mg of bacampicillin was significantly higher than the 6.8 mg/liter noted after a nearly equimolar dose of 500 mg of ampicillin. A linear relationship was also seen between dose and area under the serum concentration-time curve. Preliminary antibiotic concentration studies in five patients indicated therapeutic levels in peritonsillar pus. Beta-streptococci alone or in combination with anaerobes were isolated from about half of the abscesses, whereas anaerobes were isolated from the other half. Treatment was supplemented by surgical procedures in the majority of cases. The clinical effect was good in all treatment groups, with only one relapse. All beta-streptococci were eliminated during therapy. The total number of gastrointestinal side effects was significantly lower in patients treated with bacampicillin, although the difference in frequency of diarrhea alone was not significant.