Nirmatrelvir and ritonavir and Olanzapine and fluoxetine interaction

Nirmatrelvir and ritonavir and Olanzapine and fluoxetine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

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

Major

…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,…

Contraindicationsby drug classView label on DailyMed
Major

Antipsychotics lurasidone, pimozide ↑ lurasidone ↑ pimozide Co-administration contraindicated due to serious and/or life-threatening reactions such as cardiac arrhythmias [see Contraindications (4) ] .

Drug interactionsby drug classView label on DailyMed
Major

Sedative/hypnotics triazolam, oral midazolam ↑ triazolam ↑ midazolam Co-administration contraindicated due to potential for extreme sedation and respiratory depression [see Contraindications (4) ] .

Drug interactionsby drug classView label on DailyMed
Major

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) ] .

Drug interactionsby drug classView label on DailyMed
Moderate

Antidepressants bupropion ↓ bupropion and active metabolite hydroxy-bupropion Monitor for an adequate clinical response to bupropion. trazodone ↑ trazodone Adverse reactions of nausea, dizziness, hypotension, and syncope have been observed following co-administration of trazodone and ritonavir.

Drug interactionsby drug classView label on DailyMed

From the Olanzapine and fluoxetine label · effective 2026-03-31

Minor

Drugs Metabolized by CYP3A — In vitro studies utilizing human liver microsomes suggest that olanzapine has little potential to inhibit CYP3A.

Drug interactionsby drug classView label on DailyMed
Minor

In addition, in vitro studies have shown ketoconazole, a potent inhibitor of CYP3A activity, to be at least 100 times more potent than fluoxetine or norfluoxetine as an inhibitor of the metabolism of several substrates for this enzyme, including astemizole, cisapride, and midazolam.

Drug interactionsby drug classView label on DailyMed

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Not 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.