Oral Propionyl Erythromycin in Treating Early Syphilis

In a search for alternate schedules of treatment for patients with syphilis who are sensitive to penicillin, the Public Health Service conducted an evaluation of oral propionyl erythromycin. Although oral therapy has never been favored for the treatment of venereal disease clinic patients, it was the only form of the other antibiotics that proved practical for outpatient therapy. Three schedules were used for the treatment of 554 patients with early syphilis; 10, 15, and 20 grams given in a period of 8 to 10 days. Twenty-nine percent of the patients complained of discomfort, principally gastrointestinal, but it was not necessary to discontinue treatment because of reactions. The cumulative re-treatment rate in previously untreated darkfield-positive early syphilis was 37 percent for the 10-gram schedule and 15 percent for the 15- and 20-gram schedules. Oral erythromycin was apparently more effective in the treatment of females than males, probably because of their greater adherence to the treatment schedule. In previously untreated secondary syphilis, the early stage least amenable to treatment, the cumulative re-treatment rate for non-white patients on the 10-gram schedule was 21 percent for females and 64 percent for males. No treatment failures were observed in females treated with 15 or 20 grams, but the cumulative re-treatment rate for males was 19 percent.