Rifampin and Rifapentine interaction
Rifampin and Rifapentine: the Rifapentine prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Rifapentine (Priftin) label · effective 2026-02-06
Do not use PRIFTIN as a once-weekly continuation phase regimen in HIV-infected patients with active pulmonary tuberculosis because of a higher rate of failure and/or relapse with rifampin-resistant organisms [see Clinical Studies (14.1) ] .
Rifampin has been reported to accelerate the metabolism and may reduce the activity of the following drugs; hence, PRIFTIN may also increase the metabolism and decrease the activity of these drugs.
Porphyria Porphyria has been reported in patients receiving rifampin, attributed to induction of delta amino levulinic acid synthetase.
Interactions with Laboratory Tests Therapeutic concentrations of rifampin have been shown to inhibit standard microbiological assays for serum folate and Vitamin B 12 .
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.