The impact of rifampin drug interactions on tuberculosis preventive treatment completion and safety

<sec><title>BACKGROUND</title>Rifamycin TB preventive treatment (TPT) is critical to TB elimination. However, clinicians may be reluctant to recommend it over concerns related to drug-drug interactions (DDI). In this secondary analysis of data from the 2R² randomised clinical trial (comparing standard dose rifampin to high-dose rifampin for TPT), we investigate if participants taking medications with potential rifampin DDI had similar TPT completion, safety, and follow-up visits compared to those without.</sec><sec><title>METHODS</title>Data on concomitant medications, adverse events, treatment completion, and follow-up visits were compared between participants with and without potential rifampin DDI. Analyses were conducted with R, reporting risk difference (RD) using g-computation with logistic regression.</sec><sec><title>RESULTS</title>282 of 1,368 participants (21%) were taking essential medications with potential rifampin DDI. There was no RD in TPT completion (RD 0.04 [95% confidence interval (CI): -0.02; 0.09]) or adverse events (RD 0.02 [95% CI: -0.01; 0.06]) between participants with and without these medications. Individuals talking medications with potential DDI had a higher percentage of two or more unscheduled visits (12%) compared to those not taking them (5%) (<i>P</i> = 0.0001).</sec><sec><title>CONCLUSION</title>In participants taking medications with potential rifampin DDI, rifampin TPT can be used safely without impacting completion rates. However, additional follow-up visits should be anticipated.</sec>.