Olanzapine and fluoxetine and Perampanel interaction
Olanzapine and fluoxetine and Perampanel: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Perampanel (Fycompa) label · effective 2024-01-05
Patients should be carefully observed for signs of central nervous system (CNS) depression, such as somnolence and sedation, when FYCOMPA is used with other drugs with sedative properties because of potential additive effects.
Alcohol and Other CNS Depressants The concomitant use of FYCOMPA and CNS depressants including alcohol may increase CNS depression.
These effects may also be seen when FYCOMPA is used in combination with other CNS depressants.
Patients should limit activity until they have experience with concomitant use of CNS depressants (e.g., benzodiazepines, narcotics, barbiturates, sedating antihistamines).
From the Olanzapine and fluoxetine label · effective 2026-03-31
Carbamazepine : Potential for elevated carbamazepine levels and clinical anticonvulsant toxicity ( 7.7 )
Phenytoin : Potential for elevated phenytoin levels and clinical anticonvulsant toxicity ( 7.7 )
Carbamazepine — Patients on stable doses of carbamazepine have developed elevated plasma anticonvulsant concentrations and clinical anticonvulsant toxicity following initiation of concomitant fluoxetine treatment.
Drugs Metabolized by CYP3A — In vitro studies utilizing human liver microsomes suggest that olanzapine has little potential to inhibit CYP3A.
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.
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.