Carbamazepine and Olanzapine and fluoxetine interaction
Carbamazepine 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.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Carbamazepine (EQUETRO) label · effective 2025-08-19
Known hypersensitivity to tricyclic antidepressants ( 4 )
CNS Depressants The concomitant use of EQUETRO and other CNS depressants can increase the risk of respiratory depression, profound sedation, hypotension, and syncope.
Increased Intraocular Pressure Carbamazepine has mild anticholinergic activity.
Consider reducing the dose of CNS depressants or EQUETRO when using these drugs concomitantly.
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From the Olanzapine and fluoxetine label · effective 2026-03-31
Inducers of 1A2 — Carbamazepine therapy (200 mg BID) causes an approximate 50% increase in the clearance of olanzapine.
Higher daily doses of carbamazepine may cause an even greater increase in olanzapine clearance [see Drug Interactions ( 7.7 )] .
Carbamazepine : Potential for elevated carbamazepine levels and clinical anticonvulsant toxicity ( 7.7 )
Phenytoin : Potential for elevated phenytoin levels and clinical anticonvulsant toxicity ( 7.7 )
This increase is likely due to the fact that carbamazepine is a potent inducer of CYP1A2 activity.
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.