Ampicillin therapy for pharyngeal gonorrhea.

Single-dose oral ampicillin trihydrate is ineffective for the treatment of pharyngeal gonorrhea. An evaluation was made of the efficacy of extended oral ampicillin therapy. The regimen consisted of a single oral 3.5-g dose of ampicillin trihydrate and 1.0 g of probenecid on the first day, followed by 500 mg of ampicillin tridhydrate four times a day for each of the succeeding two days, for a total ampicillin trihydrate dose of 7.5 g. One or two follow-up cultures taken within 35 days of completion of therapy were obtained in 77 of the 101 patients treated. Positive test-of-cure cultures were reported in three persons, two of whom may have been reinfected. The failure rate was calculated to range between 1.3% (1/77) to 3.9% (3/77). This compares favorably with current recommended modes of therapy.