Buspirone and Nirmatrelvir and ritonavir interaction
Buspirone and Nirmatrelvir and ritonavir: 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 Nirmatrelvir and ritonavir (Paxlovid) label · effective 2026-02-19
Sedative/hypnotics buspirone, clorazepate, diazepam, estazolam, flurazepam, zolpidem ↑ sedative/hypnotic A dose decrease may be needed for these drugs when co-administered with PAXLOVID and monitoring for adverse events. midazolam (administered parenterally) ↑ midazolam Co-administration of midazolam (parenteral) should be done in a setting which ensures close…
From the Buspirone (Buspirone Hydrochloride) label · effective 2026-03-18
Other inhibitors and inducers of CYP3A4: Substances that inhibit CYP3A4, such as ketoconazole or ritonavir, may inhibit buspirone metabolism and increase plasma concentrations of buspirone while substances that induce CYP3A4, such as dexamethasone or certain anticonvulsants (phenytoin, phenobarbital, carbamazepine), may increase the rate of buspirone metabolism.
Consequently, when administered with a potent inhibitor of CYP3A4, a low dose of buspirone used cautiously is recommended.
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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.