Primaquine and Tacrolimus interaction
Primaquine and Tacrolimus: the Primaquine prescribing label describes 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
QT Interval Prolonging Drugs The pharmacodynamic interaction potential to prolong the QT interval of the electrocardiogram between Primaquine phosphate Tablets and other drugs that effect cardiac conduction is unknown.
If Primaquine phosphate Tablets are used concomitantly with other drugs that prolong the QT interval, close and frequent electrocardiogram monitoring is advised (see PRECAUTIONS , ADVERSE REACTIONS , and OVERDOSAGE ).
CYP3A4 Substrates Refer to the Prescribing Information for a CYP3A substrate where minimal concentration changes may lead to serious adverse reactions (e.g. rivaroxaban, calcineurin inhibitors, ergot derivatives, tyrosine kinase inhibitors) for the recommended dosage modification and/or monitoring.
Increase monitoring for adverse reactions associated with CYP3A4 substrate drugs that prolong the QT interval (e.g., pimozide) or where minimal concentration changes may lead to serious adverse reactions when concurrently administered with Primaquine phosphate Tablets.
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.