1139. Comparative Effectiveness of 1 Dose versus 3 Doses of Benzathine Penicillin in the Treatment of Early Syphilis in HIV-infected Patients: A Multicenter, Prospective Observational Study in Taiwan
Session: Oral Abstract Session: Sexually Transmitted Infections
Friday, October 4, 2013: 2:15 PM
Room: The Moscone Center: 250-262
Background: Both 3 doses and 1 dose of benzathine penicillin G (BPG) have been used in treatment of early syphilis among HIV-infected patients. However, effectiveness between the two regimens has rarely been compared before.

Methods: We conducted a prospective observational study in 8 hospitals around Taiwan between 2007 and 2012 to compare the effectiveness between 1 and 3 doses of BPG among HIV-infected adult patients with early syphilis. Rapid plasma reagin (RPR) titers were followed every 3-6 months after treatment. Primary end point was at least 4-fold decline of RPR titer from baseline by 12 months of follow-up. Treatment failure was defined as failure to achieve 4-fold decline of RPR titer by 12 months; or an increase of RPR titer by 4-fold after ever achieving response. Missing data were treated by following the last-observation-carried-forward principle. The planned sample size was 260 for each group to demonstrate the non-inferiority of 1 dose to 3 doses (response rate, 75%; non-inferiority margin, 10%; 80% power, and one-sided type I error 0.05)

Results: During the study period, 542 HIV-infected patients were enrolled. The two groups of patients did not differ significantly in mean age (1 vs 3 doses, 32.5 vs 33.7 years), RPR titer (median, 64), and proportion of MSM (95.3 vs 92.0%), previous syphilis (33.9 vs 36.5%), primary and secondary syphilis (74.7 vs. 65.4%), on HAART (64.2 vs 60.1%), CD4 <350 cells/μL(33.9 vs 37.6%), and plasma HIV RNA load <400 copies/ml (52.4 vs 53.5%). At 6th month of follow-up, serologic response was 196/271 (72.3%) for 1-dose group and 184/271 (68.0%) for 3-dose group (P=0.30). At 12th month of follow-up, the response rate was 68.3% (185/271) for 1-dose group and 74.5% (202/271) for 3-dose group (difference, 6.2%; 90% CI, -12.6 to 1.0%). Patients in 1-dose group experienced treatment failure much earlier than those in 3-dose group during the follow-up for 1184 days (IQR, 1047-1322) (log-rank P=0.03). In multivariate analysis, CD4>350 cells/μL (OR, 1.50; 95% CI, 1.02-2.21) and secondary syphilis (OR, 1.75; 95% CI, 1.20-2.56) were associated with treatment response at 12 months of follow-up.

Conclusion: We failed to demonstrate that the effectiveness of 1 dose was non-inferior to that of 3 doses of BPG in treatment of early syphilis among HIV-infected patients in the HAART era. CD4 >350 cells/μL and secondary syphilis were associated with treatment response to BPG.

Chien-Ching Hung, MD, MIH, PhD, Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, Chia-Jui Yang, MD, Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan and Taiwan HIV Infection and Syphilis Study Group


C. C. Hung, None

C. J. Yang, None

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