Self-administered 3HP associated with high treatment completion for latent TB
Self-administered isoniazid-rifapentine taken once weekly — a regimen called 3HP — was associated with higher treatment completion rates for latent tuberculosis infection compared with daily rifampin, according to a study.
Treatment completion was even more likely among older adults on 3HP than those aged 18 to 39 years, researchers reported.
The study compared treatment completion rates between patients taking once-weekly 3HP by self-administered therapy (3HP-SAT) to 4 months of daily rifampin (4R). Both 3HP and 4R were ranked as preferred regimens for treating latent TB infection (LTBI) in new CDC guidelines released this year.
“We have been treating patients with latent tuberculosis infection using these short-course regimens for several years, but they had never been compared head to head,” Michelle K. Haas, MD, assistant professor of medicine in the division of infectious diseases at the University of Colorado, told Healio. “We were interested in evaluating how the two treatments compared.”
Haas and colleagues performed a retrospective cohort study of adults aged 18 years or older initiating LTBI treatment with one of the two regimens in a United States-based TB clinic between April 11, 2016, and Dec. 31, 2018. According to the study, the researchers evaluated treatment completion through pharmacy fills and chart reviews.
Throughout the study, 560 individuals (42%) initiated 3HP-SAT and 773 (58%) initiated 4R. The study demonstrated that among participants aged 18 to 49 years, treatment completion with 3HP-SAT was 79% compared to 68% with 4R (adjusted RR [aRR] = 1.17; 95% CI, 1.17-1.27). Among those aged 50 years or older, treatment completion was 87% with 3HP-SAT and 64% with 4R (aRR = 1.35; 95% CI, 1.19-1.52).
Additionally, the study showed that there was no difference in risk for adverse events in the 18 to 49 years age group (aRR = 0.93; 95% CI, 1.48-0.75), and a reduced risk for adverse events among patients aged 50 years or older who received 3HP-SAT (aRR = 0.37; 95% CI, 0.16-0.85).
“Self-administered, once-weekly isoniazid and rifapentine should be offered as an option for treating people with latent TB infection,” Haas said.