A single dose of benzathine penicillin G appeared to be as effective as multiple doses in the treatment of early syphilis in HIV-infected individuals with preserved CD4 counts, according to recent study results.
Despite current guidelines recommending the use of a single dose of 2.4 million units of benzathine penicillin G (BPG) for the treatment of early stages of syphilis regardless of HIV serostatus, infectious disease specialists are reluctant to use only one dose in patients with HIV due to potential insufficiency and that data supporting the single-dose recommendation date back to the pre-HIV era, researchers wrote.
To assess the adequacy of a single dose, the researchers collected data on 350 patients (99% men) from the US Military HIV Natural History Study, a database for Department of Defense beneficiaries.
Treatment response was evaluated at 13 months and was defined as at least a fourfold decrease in NTr titer.
The researchers found that among the participants, there were 478 syphilis cases. Of these, 393 underwent a regimen of BPG only, 141 of whom received a single dose. The number of BPG doses received did not appear to influence treatment response (reference one dose of BPG; HR=1.11; 95% CI, 0.9-1.4), with a 92% response rate in both groups. Multivariate analysis indicated that older age (HR=0.82 per 10-year increase; 95% CI, 0.73-0.93) was linked to delays in treatment response. Faster treatment response was observed in patients with greater pretreatment titers (reference NTr titer<1:64; HR=1.94; 95% CI, 1.58-2.39) and CD4 counts (HR=1.07 for every 100 cell increase; 95% CI, 1.01-1.12).
“The results of our study support the use of a single dose of BPG for the treatment of early syphilis in HIV-infected persons with preserved CD4 counts. Overall, serologic failure is uncommon,” the researchers wrote. “When close follow-up can be ensured, HIV-infected persons with preserved CD4 counts and delayed NTr responses can be followed safely for a year and perhaps even 2 years without additional treatment courses.”
Disclosure: The researchers report no relevant financial disclosures.