RANDOMIZED EVALUATION OF BENZATHINE PENICILLIN-V TWICE-DAILY VERSUS POTASSIUM PENICILLIN-V 3 TIMES DAILY IN THE TREATMENT OF GROUP-A STREPTOCOCCAL PHARYNGITIS

In a randomized, prospective, multicenter study the clinical and bacte riological efficacies of three dosage schedules with two different sal ts of oral penicillin V suspensions (regimen 1: potassium salt of peni cillin V, 50,000 U/kg of body weight per day in three divided doses; r egimen 2: benzathine salt of penicillin V, 50,000 U/kg of body weight per day in two divided doses; and regimen 3: benzathine salt of penici llin V, 100,000 U/kg of body weight in two divided doses) for the trea tment of streptococcal pharyngitis were evaluated. Children with clini cal signs of acute pharyngitis and a positive throat culture for group A beta-hemolytic streptococci (GABHS) were eligible. There was no dif ference between the treatment groups with respect to the overall clini cal success rate. Eradication of the original serotype of GABHS from t hroat cultures was achieved in 87.1 % (regimen 1), 85.5 % (regimen 2) and 87.7 % (regimen 3) of patients. The incidence of potential drug-re lated adverse events was significantly higher in patients treated with regimen 3. The results of this and earlier studies strongly suggest t hat oral penicillin given twice daily should be the recommended treatm ent for the initial treatment of pharyngitis due to GABHS. Doubling th e total daily dose is not beneficial in the usual clinical setting. Be cause of its favorable pharmacokinetics, the benzathine salt of penici llin V appears to be well suited for a twice-a-day dosage schedule.