April 1, 2011
Noting that "the optimal antimicrobial regimen to treat syphilis in HIV-infected subjects remains controversial," the study authors conducted a systematic literature assessment of studies evaluating syphilis treatment regimens in this population.
Studies published between 1980 and June 2008 in electronic databases, trial registries and bibliographies (with no language restrictions) were independently evaluated for content and quality. Those that involved 10 or more people, with documented HIV status, type and duration of syphilis treatment, as well as at least six months of follow-up, were included. The main outcome was syphilis serological or clinical failure stratified by syphilis stage.
The systematic review included 23 studies (22 published papers, 1 conference abstract), of the 1,380 unique citations. Pooled summary statistics could not be generated on account of the significant heterogeneity among studies. "The range of probabilities for serological failure with 2.4 million units (MU) of intramuscular benzathine penicillin G (BPG) was 6.9 percent (95 percent CI 2.6 percent to 14.4 percent) to 22.4 percent (11.7 percent to 36.6 percent); that of 7.2 MU of BPG in late latent syphilis was 19.4 percent (11.9 percent to 28.9 percent) to 31.1 percent (22.3 percent to 40.9 percent) and failure estimates with 18-24 MU of aqueous penicillin for the treatment of neurosyphilis were 27.3 percent (6.0 percent to 61.0 percent) to 27.8 percent (14.2 percent to 45.2 percent)," according to the results.
"The optimal antimicrobial regimen to treat syphilis in HIV-infected subjects is unknown; guideline recommendations in this population are based on little objective data," the authors concluded.