Introduction

Antimicrobials like clindamycin and amoxicillin/clavulanic acid are clinically effective in pharyngotonsillitis caused by group A beta-hemolytic streptococci (GABHS) in which an increasing rate of treatment failure has been observed with penicillin and other beta-lactam antibiotics.

Aim

To compare oral clindamycin with oral amoxicillin/clavulanic acid for their clinical and bacteriologic efficacy and tolerability in the outpatient treatment of acute recurrent GABHS pharyngotonsillitis.

Patient Profile

• 774 patients (12 to 60 years of age) with acute recurrent GABHS pharyngotonsillitis

Method

Study Design

• International, multicenter, randomized, investigator-blinded, prospective study
• Patients were randomly assigned to receive oral clindamycin 300 mg BID or oral amoxicillin/clavulanic acid 1 g (875 mg amoxicillin/125 mg clavulanic acid) BID for 10 consecutive days

Endpoints

• Primary end points: clinical and bacteriologic efficacy assessed on day 12, and clinical and bacteriologic recurrence rates assessed up to 3 months after treatment completion
• Secondary end point: tolerability

Results

Efficacy

• Clindamycin achieved significantly higher clinical cure rates as compared to amoxicillin/clavulanic acid therapy (92.6% vs. 85.2%, resp., P<0.003) at day 12 (Figure 1)
• A comparable bacteriologic eradication was achieved with clindamycin (97.9%) and amoxicillin/clavulanic acid (94.4%) in the patients at day 12
• At 3-month follow-up, similar clinical cure and bacteriologic eradication was achieved with clindamycin (95.4% and 99.2%) and amoxicillin/clavulanic acid (95.7% and 99.6%) was achieved

Figure 1: Comparison of the effects of clindamycin and amoxicillin/clavulanic acid therapy on study endpoints

Safety 

• Both clindamycin and amoxicillin/clavulanic acid treatments were well tolerated
• Adverse events were reported in 13.8% patients in the clindamycin group and 10.5% patients in the amoxicillin/clavulanic acid group
• The most commonly reported adverse events involved the digestive system, mainly diarrhea (8.6% in the clindamycin group vs. 5.6% in the amoxicillin/clavulanic acid group)
• No serious adverse events were reported during the study
• No adverse events required early termination of treatment

  Conclusion

• Clindamycin achieved significantly greater clinical cure rates at day 12 in patients with acute recurrent GABHS pharyngotonsillitis
• Both clindamycin and amoxicillin/clavulanic acid achieved comparable rates of bacteriologic eradication at 12 days and 3 months and comparable clinical cure rates at 3 months

Clin Ther. 2006; 28: 99-109