Cladribine and Efavirenz interaction
Cladribine and Efavirenz: both prescribing labels flag 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 Cladribine (Mavenclad) label · effective 2026-05-27
Antiviral and antiretroviral drugs: Avoid concomitant use.
Antiviral and Antiretroviral Drugs Clinical Impact Compounds that require intracellular phosphorylation to become active (e.g., lamivudine, zalcitabine, ribavirin, stavudine, and zidovudine) could interfere with the intracellular phosphorylation and activity of cladribine.
From the Efavirenz label · effective 2024-03-31
Immunosuppressants: Cyclosporine, tacrolimus, sirolimus and others metabolized by CYP3A ↓ immunosuppressant Dose adjustments of the immunosuppressant may be required.
Close monitoring of immunosuppressant concentrations for at least 2 weeks (until stable concentrations are reached) is recommended when starting or stopping treatment with efavirenz.
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.