Critical
Rifampicin × ritonavir
Antituberculous antibiotic×HIV protease inhibitor / pharmacokinetic booster
Mechanism
Strong CYP3A4 inducer. Ritonavir falls 35%, darunavir/atazanavir within regimen fall 80%. ART failure.
Symptoms
Rising viral load.
Management
Combination contraindicated. Alternatively for TB – switch rifampicin to rifabutin (weaker induction).
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.