What the FDA labels say about taking them together
Fluoxetine and olanzapine
Fluoxetine's FDA label of January 8, 2026 names olanzapine in its boxed warning section, and olanzapine's label names fluoxetine too. The olanzapine label: “Increased clearance of olanzapine. Fluvoxamine: May increase olanzapine levels. ZYPREXA and Fluoxetine in Combination:”
Check it at the source: the fluoxetine FDA label on DailyMed (effective January 8, 2026, Dista Products Company); the olanzapine FDA label on DailyMed (effective March 5, 2026, Macleods Pharmaceuticals Limited).
What does the fluoxetine label say about olanzapine?
Fluoxetine label, boxed warningWhen using PROZAC and olanzapine in combination, also refer to Boxed Warning section of the package insert for Symbyax.
Fluoxetine label, drug interactionsMay potentiate the risk of bleeding ( 7.4 ) Drugs Tightly Bound to Plasma Proteins: May cause a shift in plasma concentrations ( 7.6 , 7.7 ) Olanzapine:
Fluoxetine label, warnings and precautionsIt should be noted that PROZAC is approved in the pediatric population for Major Depressive Disorder and Obsessive Compulsive Disorder; and PROZAC in combination with olanzapine for the acute treatment of depressive episodes associated with Bipolar I Disorder.
Source: FDA drug label (Prozac), NDA018936 (Eli Lilly And Co), as published by Dista Products Company, effective January 8, 2026 (SPL set c88f33ed-6dfb-4c5e-bc01-d8e36dd97299), via openFDA; the full label on DailyMed
What does the olanzapine label say about fluoxetine?
Olanzapine label, boxed warningOlanzapine is not approved for the treatment of patients with dementia-related psychosis [see Warnings and Precautions ( 5.1 ), Use in Specific Populations ( 8.5 ), and Patient Counseling Information ( 17 )] When using olanzapine and fluoxetine in combination, also refer to the Boxed Warning section of the package insert for Symbyax.
Olanzapine label, contraindicationsWhen using olanzapine and fluoxetine in combination, also refer to the Contraindications section of the package insert for Symbyax.
Olanzapine label, drug interactionsInhibitors of CYP2D6 Fluoxetine: Fluoxetine (60 mg single dose or 60 mg daily dose for 8 days) causes a small (mean 16%) increase in the maximum concentration of olanzapine and a small (mean 16%) decrease in olanzapine clearance.
Olanzapine label, warnings and precautionsThe possibility of a suicide attempt is inherent in schizophrenia and in bipolar I disorder, and close supervision of high-risk patients should accompany drug therapy; when using in combination with fluoxetine, also refer to the Boxed Warning and Warnings and Precautions sections of the package insert for Symbyax.
Source: FDA drug label (Olanzapine), Macleods Pharmaceuticals Limited, effective March 5, 2026 (SPL set 8e095987-bdea-42f2-9550-c7155cf07d30), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Fluoxetine | Olanzapine | |
|---|---|---|
| Labeled for | Depression, Anxiety, Bipolar disorder | Schizophrenia, Bipolar disorder, Depression |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0519 per capsule 40 mg capsule | $0.147 per tablet 20 mg tablet |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once