Efavirenz, lamivudine, and tenofovir and Primaquine interaction
Efavirenz, lamivudine, and tenofovir and Primaquine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Primaquine (Primaquine Phosphate) label · effective 2026-02-11
Published clinical reports indicate primaquine may inhibit CYP3A4 enzyme activity and thus may lead to increased exposure of oral CYP3A4 substrate drugs when co-administered with Primaquine phosphate Tablets.
From the Efavirenz, lamivudine, and tenofovir (SYMFI) label · effective 2019-10-15
Antimalarials: Artemether/lumefantrine ↓ artemether ↓ dihydroartemisinin ↓ lumefantrine Consider alternatives to artemether/lumefantrine because of the risk of QT interval prolongation [see Warnings and Precautions (5.16) ] .
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.