Retreatment Rates for Uncomplicated Gonorrhea: Comparing Ceftriaxone and Azithromycin Versus Ceftriaxone and Doxycycline

Background:  The CDC currently favors the combination of Ceftriaxone (CTX) and Azithromycin (AZM) over CTX and Doxycycline(DOXY) for treatment of uncomplicated Neisseria gonorrhoeae infections (GC).

Objectives:  To retrospectively compare retreatment rates between patients receiving CTX+AZM and those receiving CTX+DOXY.

Methods:  We analyzed clinic records for all patients diagnosed with uncomplicated GC at either of Baltimore’s two public STD clinics between January 1, 2004 – April 30, 2011, and measured time to retreatment at either STD clinic from the date when the CTX regimen was administered.  Patients were censored two years after treatment was received or on June 30, 2011, whichever came first.  Kaplan-Meier curves were plotted to compare retreatment rates between the two groups.

Results:  Between January 2004 – April 2011, 7,806 persons were diagnosed with uncomplicated GC, nearly half of whom (47.5%) received either CTX+AZM (n=1,155, 31.1%) or CTX + DOXY (2,556, 68.9%).  There was no significant MIC shift for ceftriaxone between 2004 and 2011 while doxycycline resistance increased from 9% to 13%.  Overall, 331 (8.9%) were retreated for GC within two years of the initial CTX regimen, with a median of 7.4 months (IQR: 9.8) between the CTX regimen and retreatment. The retreatment rate was slightly lower among those receiving CTX+AZM (93, 8.0%) than among those receiving CTX+DOXY (238, 9.3%); median time to retreatment was shorter among those receiving CTX+DOXY compared to CTX+AZM (7.0 and 8.7 months, respectively), though these differences were not statistically significant (Log Rank Test, p=0.16). There was no significant difference in retreatment rates between the two groups by time period.

Conclusions:  Retreatment rates for CTX+AZM were similar to those for CTX+DOXY.

Implications for Programs, Policy, and Research:  CTX+AZM did not provide enhanced efficacy in this population; the impact of these combinations on changes in GC antimicrobial resistance patterns over time is not known.