A Retrospective Comparative Study of 2-Drug Oral and Intramuscular Cephalosporin Treatment Regimens for Pharyngeal Gonorrhea

Background. The Centers for Disease Control and Prevention guidelines for pharyngeal gonorrhea treatment recommend dual therapy with intramuscular ceftriaxone and either azithromycin or doxycycline. Few clinical data exist to support this recommendation. Methods. We conducted a retrospective analysis of patients diagnosed with pharyngeal gonorrhea during 1993-2011, at a sexually transmitted disease clinic in Seattle, Washington, and compared the proportion of repeat positive tests for pharyngeal gonorrhea 7-180 days following treatment among persons receiving different drug regimens. Associations of treatment regimens were assessed using relative risks through Poisson regression models with log link and robust standard errors. Results. A total of 1440 cases of pharyngeal gonorrhea were diagnosed during the study period, 25% of which (n = 360) underwent retesting. Among retested patients, the risk of repeat positive test was lowest among persons receiving an oral cephalosporin and azithromycin (7%, reference group), and highest among those receiving an oral cephalosporin alone (30%; relative risk [RR], 3.98; 95% confidence interval [CI], 1.70-9.36) or in combination with doxycycline (33%; RR, 4.18; 95% CI, 1.64-10.7). The risk of repeat test positivity did not significantly differ between persons treated with an oral cephalosporin and azithromycin and those treated with ceftriaxone alone (9.1%; RR, 0.81; 95% CI,.18-3.60) or ceftriaxone combined with azithromycin or doxycycline (11.3%; RR, 1.20; 95% CI,.43-3.33). Conclusions. In this retrospective study, dual therapy with an oral third-generation cephalosporin and azithromycin was comparable to ceftriaxone-based regimens in the treatment of pharyngeal gonorrhea. Combination oral therapy with doxycycline was associated with an elevated risk of persistent or recurrent infection.