Treatment completion for latent tuberculosis infection: a retrospective cohort study comparing 9 months of isoniazid, 4 months of rifampin and 3 months of isoniazid and rifapentine.

BACKGROUND: The U.S. Centers for Disease Control and Prevention (CDC) recommended a new regimen for treatment of latent tuberculosis (three months of weekly isoniazid and rifapentine) in late 2011. While completion rates of this regimen were reported to be higher than nine months of isoniazid, little is known about the completion rates of three months of isoniazid and rifapentine compared to nine months of isoniazid or four months of rifampin in actual use scenarios. METHODS: We conducted a retrospective cohort study comparing treatment completion for latent tuberculosis (TB) infection in patients treated with nine months of isoniazid, three months of isoniazid and rifapentine or four months of rifampin in outpatient clinics and a public health TB clinic in Seattle, Washington. The primary outcome of treatment completion was defined as 270 doses of isoniazid within 12 months, 120 doses of rifampin within six months and 12 doses of isoniazid and rifapentine within four months. RESULTS: Three hundred ninety-three patients were included in the study. Patients were equally likely to complete three months of weekly isoniazid and rifapentine or four months of rifampin (85% completion rate of both regimens), as compared to 52% in the nine months of isoniazid group (p < 0.001). These associations remained statistically significant even after adjusting for clinic location and type of monitoring. Monitoring type (weekly versus monthly versus less often than monthly) had less impact on treatment completion than the type of treatment offered. CONCLUSIONS: Patients were equally as likely to complete the three months of isoniazid and rifapentine as four months of rifampin. Four months of rifampin is similar in efficacy compared to placebo as isoniazid and rifapentine but does not require directly observed therapy (DOT), and is less expensive compared to combination therapy with isoniazid and rifapentine, and thus can be the optimal treatment regimen to achieve the maximal efficacy in a community setting.

Selenium supplementation in HIV-infected patients: is there any potential clinical benefit?

In HIV-infected patients undergoing antiretroviral therapy, the question of whether selenium supplementation has any therapeutic benefit is still open. With recent popular coverage of this issue, many patients have considered using selenium. Clinicians have a duty to ensure that the recommendations they make to their patients are evidence based. The literature search reported here showed that evidence to support standard selenium supplementation in patients with HIV is both limited and insufficient. To definitively answer this clinical question, the overall effect of selenium supplementation would need to be evaluated in a large randomized, controlled trial with solid methodology and strong internal validity. Although the available evidence for selenium supplementation is weak, its low toxicity and side effect profile seem to pose minimal risks, especially at low doses. For patients who want to add selenium to their regimen, discussing the potential risks and benefits as well as close follow-up is warranted.