Olanzapine and fluoxetine and Ranolazine interaction
Olanzapine and fluoxetine and Ranolazine: 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 Olanzapine and fluoxetine label · effective 2026-03-31
Use olanzapine and fluoxetine capsules with caution in combination with other drugs that prolong the QT interval ( 4.2 , 5.20 , 7.7 , 7.8 ) 7.1 Monoamine Oxidase Inhibitors (MAOIs) [See Dosage and Administration ( 2.4 , 2.5 ), Contraindications ( 4.1 ), and Warnings and Precautions ( 5.6 )] .
The Effect of Other Drugs on Olanzapine — Fluoxetine, an inhibitor of CYP2D6, decreases olanzapine clearance a small amount [see Clinical Pharmacology ( 12.3 )].
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.
From the Ranolazine (ASPRUZYO SPRINKLE) label · effective 2025-01-29
Drugs transported by P-gp (e.g., digoxin), or drugs metabolized by CYP2D6 (e.g., tricyclic antidepressants) may need reduced doses when used with ASPRUZYO Sprinkle.
Drugs Metabolized by CYP2D6 The exposure to CYP2D6 substrates, such as tricyclic antidepressants and antipsychotics, may be increased during co-administration with ASPRUZYO Sprinkle, and lower doses of these drugs may be required.
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.