A comparative study of clarithromycin and penicillin VK in the treatment of outpatients with streptococcal pharyngitis.

This double-blind, randomized 17-centre clinical trial compared the safety and efficacy of clarithromycin (2 x 125 mg capsules) 12-hourly and penicillin VK (2 x 125 mg tablets in capsules) 6-hourly in the treatment of proven Group A, beta-haemolytic streptococcal pharyngitis. One hundred and twenty-eight patients (clarithromycin: 65, penicillin VK: 63) were enrolled in the study and included in the safety analysis. Clinical and bacteriological evaluations were performed on treatment days 5-7, and within two to ten and 15 to 56 days post-treatment. The post-treatment clinical success and bacteriological cure rates for clarithromycin were 95% (41/43) and 88% (38/43), respectively, with both rates 91% (43/47) for penicillin VK. Three clarithromycin patients withdrew because of adverse events, but only one of these events was possibly drug related. More clarithromycin patients (19/65) reported digestive system related adverse events than did penicillin VK patients (8/63); however, there was no significant difference between treatment groups in the overall number of patients reporting adverse events. Clarithromycin (250 mg, 12-hourly) is a safe and effective as penicillin VK (250 mg, 6-hourly) in the treatment of streptococcal pharyngitis.