Nirmatrelvir and ritonavir and Quetiapine interaction
Nirmatrelvir and ritonavir and Quetiapine: 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
…Antiarrhythmic: amiodarone, dronedarone, flecainide, propafenone, quinidine • Anti-gout: colchicine (in patients with renal and/or hepatic impairment [see Table 2 , Drug Interactions (7.3)] ) • Antipsychotics: lurasidone, pimozide • Benign prostatic hyperplasia agents: silodosin • Cardiovascular agents: eplerenone, ivabradine • Ergot derivatives: dihydroergotamine, ergotamine,…
Antipsychotics lurasidone, pimozide ↑ lurasidone ↑ pimozide Co-administration contraindicated due to serious and/or life-threatening reactions such as cardiac arrhythmias [see Contraindications (4) ] .
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) ] .
Refer to the quetiapine prescribing information for recommendations. clozapine ↑ clozapine If co-administration is necessary, consider reducing the clozapine dose and monitor for adverse reactions.
From the Quetiapine (SEROQUEL XR) label · effective 2026-04-10
• Concomitant use of strong CYP3A4 inhibitors: Reduce quetiapine dose to one‑sixth when coadministered with strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) ( 2.5 , 7.1 , 12.3 )
Quetiapine exposure is increased by the prototype CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.) and decreased by the prototype of CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, avasimibe, St.
CYP3A4 inhibitors: Coadministration of ketoconazole, a potent inhibitor of cytochrome CYP3A4, resulted in significant increase in quetiapine exposure.
The dose should be reduced to one‑sixth of the original dose in patients coadministered with a strong CYP3A4 inhibitor [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3) ].
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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.