Pharmacokinetic interaction of rifapentine and raltegravir in healthy volunteers

Objectives: Latent tuberculosis infection and tuberculosis disease are prevalent worldwide. However, antimycobacterial rifamycins have drug interactions with many antiretroviral drugs. We evaluated the effect of rifapentine on the pharmacokinetic properties of raltegravir. Methods: In this open-label, fixed-sequence, three-period study, 21 healthy volunteers were given: raltegravir alone (400 mg every 12 h for 4 days) on days 1-4 of Period 1; rifapentine (900 mg once weekly for 3 weeks) on days 1, 8 and 15 of Period 2 and raltegravir (400 mg every 12 h for 4 days) on days 12-15 of Period 2; and rifapentine (600 mg once daily for 10 scheduled doses) on days 1, 4-8 and 11-14 of Period 3 and raltegravir (400 mg every 12 h for 4 days) on days 11-14 of Period 3. Plasma raltegravir concentrations were measured. ClinicalTrials.gov database: NCT00809718. Results: In 16 subjects who completed the study, coadministration of raltegravir with rifapentine (900 mg once weekly; Period 2) compared with raltegravir alone resulted in the geometric mean of the raltegravir AUC from 0 to 12 h (AUC. _0-12) being increased by 71%; the peak concentration increased by 89% and the trough concentration decreased by 12%. Coadministration of raltegravir with rifapentine in Period 3 did not change the geometric mean of the raltegravir AUC. _0-12 or the peak concentration, but it decreased the trough concentration by 41%. Raltegravir coadministered with rifapentine was generally well tolerated. Conclusions: The increased raltegravir exposure observed with once-weekly rifapentine was safe and tolerable. Once-weekly rifapentine can be used with raltegravir to treat latent tuberculosis infection in patients who are infected with HIV.