Guanfacine and Nirmatrelvir and ritonavir interaction
Guanfacine 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
…(selective blocker of Na v 1.8 sodium channels): suzetrigine • Opioid antagonists: naloxegol • PDE5 inhibitor: sildenafil (Revatio ® ) when used for pulmonary arterial hypertension (PAH) • Sedative/hypnotics: triazolam, oral midazolam • Serotonin receptor 1A agonist/serotonin receptor 2A antagonist: flibanserin • Vasopressin receptor antagonists: tolvaptan ➢ Drugs that…
Sedative/hypnotics triazolam, oral midazolam ↑ triazolam ↑ midazolam Co-administration contraindicated due to potential for extreme sedation and respiratory depression [see Contraindications (4) ] .
Serotonin receptor 1A agonist/ serotonin receptor 2A antagonist flibanserin ↑ flibanserin Co-administration contraindicated due to potential for hypotension, syncope, and CNS depression [see Contraindications (4) ] .
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 Guanfacine (Intuniv) label · effective 2025-06-23
…Interactions: Effect of other Drugs on INTUNIV Concomitant Drug Name or Drug Class Clinical Rationale and Magnitude of Drug Interaction Clinical Recommendation Strong and moderate CYP3A4 inhibitors, e.g., ketoconazole, fluconazole Guanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be significantly affected resulting in an increase…
Decrease INTUNIV to 50% of target dosage when coadministered with strong and moderate CYP3A4 inhibitors ( 2.7 ).
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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.