Cinacalcet and Nirmatrelvir and ritonavir interaction
Cinacalcet and Nirmatrelvir and ritonavir: 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 Cinacalcet (Sensipar) label · effective 2025-12-07
Co-administration with a strong CYP3A4 inhibitor may increase serum levels of cinacalcet.
Dose adjustment of Sensipar may be required if a patient initiates or discontinues therapy with a strong CYP3A4 inhibitor (e.g., ketoconazole, itraconazole).
Strong CYP3A4 Inhibitors Cinacalcet is partially metabolized by CYP3A4.
From the Nirmatrelvir and ritonavir (Paxlovid) label · effective 2026-02-19
Potential for PAXLOVID to Affect Other Drugs PAXLOVID (nirmatrelvir co-packaged with ritonavir) is a strong inhibitor of CYP3A, and an inhibitor of CYP2D6, P-gp and OATP1B1.
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.