Efavirenz and Flecainide interaction
Efavirenz and Flecainide: 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 Flecainide (Flecainide Acetate) label · effective 2026-02-06
Limited data in patients receiving known enzyme inducers ( phenytoin, phenobarbital, carbamazepine ) indicate only a 30% increase in the rate of flecainide elimination.
From the Efavirenz label · effective 2024-03-31
QT Prolonging Drugs There is limited information available on the potential for a pharmacodynamic interaction between efavirenz and drugs that prolong the QTc interval.
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.