The natural history of recurrent acute tonsillitis and a clinical trial of azithromycin for antibiotic prophylaxis.

The pharmacokinetics of azithromycin (Zitromax), Pfizer Inc., USA) in tonsil tissue warranted the present trial. In 110 patients eligible for tonsillectomy because of recurrent acute tonsillitis, surgery was replaced by randomized medication with azithromycin 500 mg or placebo once per week for 6 months. Subsequently, their clinical condition and microbiology was monitored for 12 months. Acute tonsillitis developed in 40% of the patients who received azithromycin and in 49% of the patients in the placebo group (P > 0.05). Accordingly, 45% of all patients developed acute tonsillitis. Resistance to azithromycin was not detected. In this trial long-term medication with azithromycin was not efficacious in recurrent acute tonsillitis. As all patients were eligible for tonsillectomy according to current criteria, it is surprising that only 45% developed acute tonsillitis during the trial period. Therefore, the criteria for tonsillectomy in recurrent acute tonsillitis must be revised.