Olanzapine and fluoxetine and Valbenazine interaction
Olanzapine and fluoxetine and Valbenazine: 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 Valbenazine (INGREZZA) label · effective 2026-04-17
Neuroleptic Malignant Syndrome (NMS ) A potentially fatal symptom complex referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association with drugs that reduce dopaminergic transmission.
For patients who are CYP2D6 poor metabolizers or are taking a strong CYP2D6 inhibitor, dose reduction may be necessary.
Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, drug fever, and primary central nervous system pathology.
Use of strong CYP2D6 inhibitors with INGREZZA or INGREZZA SPRINKLE Recommended dosage is 40 mg once daily.
Strong CYP2D6 Inhibitors Clinical Implication: Concomitant use of INGREZZA or INGREZZA SPRINKLE with strong CYP2D6 inhibitors increased the exposure (C max and AUC) to valbenazine’s active metabolite compared with the use of INGREZZA or INGREZZA SPRINKLE alone [see Clinical Pharmacology ( 12.3 , 12.5 )] .
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 )] .
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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.