Single Doses of Methacycline and Doxycycline for Gonorrhea: A Cooperative Study of the Frequency and Cause of Treatment Failure

Abstract

Use of single oral doses of the various congeners of tetracycline has been widely recommended as an alternative to penicillin for treatment of uncomplicated gonorrhea. However, in the present cooperative study, therapeutic failure occurred within two weeks in 45% of men in Durham given a single 300-mg oral dose of doxycycline, and in 60% of men and women in Seattle given a single 1,200-mg oral dose of methacycline. Therapeutic failure was correlated with increased resistance to tetracycline of gonococci isolated before treatment and was associated with persistent asymptomatic infection with such resistant isolates in several patients. An increasing resistance of Neisseria gonorrhoeae to the tetracyclines has been documented in Seattle during the past six years and may be both cause and effect of the poor results obtained with single-dose therapy with oral tetracycline. Repetition of the 300-mg oral dose of doxycycline after 1 hr was more effective but not well tolerated. The dose of tetracycline hydrochloride recommended by the United States Public Health Service for gonorrhea in patients with allergy to penicillin is an initial 1,500-mg oral dose, followed by 500 mg orally four times daily for four days. A single dose of oral tetracycline therapy cannot be recommended for uncomplicated gonorrhea.