What the FDA labels say about taking them together
Lithium and olanzapine
Olanzapine's FDA label of March 5, 2026 names lithium in its contraindications section; lithium's label does not name olanzapine itself but warns about its class (Atypical antipsychotics). The olanzapine label: “May elevate prolactin levels. Use in Combination with Fluoxetine, Lithium or Valproate:”
Check it at the source: the lithium FDA label on DailyMed (effective December 23, 2025, Glenmark Pharmaceuticals Inc., USA); the olanzapine FDA label on DailyMed (effective March 5, 2026, Macleods Pharmaceuticals Limited).
What does the lithium label say about olanzapine?
Lithium's label does not name olanzapine itself; it warns about its class (Atypical antipsychotics):
Lithium label, drug interactionsMonitor for neurologic adverse reactions. Atypical and Typical Antipsychotic Drugs
Lithium label, drug interactionsReports of neurotoxic reactions in patients treated with both lithium and an antipsychotic, ranging from extrapyramidal symptoms to neuroleptic malignant syndrome, as well as reports of an encephalopathic syndrome in few patients treated with concomitant therapy [see Warnings and Precautions ( 5.5 )].
Source: FDA drug label (Lithium Carbonate), Glenmark Pharmaceuticals Inc., USA, effective December 23, 2025 (SPL set 63b3790f-a9b5-47f4-bae1-ddf8b43c13c1), via openFDA; the full label on DailyMed
What does the olanzapine label say about lithium?
Olanzapine label, contraindicationsFor specific information about the contraindications of lithium or valproate, refer to the Contraindications section of the package inserts for these other products.
Olanzapine label, drug interactionsTherefore, concomitant olanzapine administration does not require dosage adjustment of lithium [see Warnings and Precautions ( 5.16 )].
Olanzapine label, warnings and precautionsUse in Combination with Fluoxetine, Lithium or Valproate: Also refer to the package inserts for Symbyax, lithium, or valproate.
Zyprexa label (H2-Pharma LLC, February 11, 2026), drug interactionsIncreased somnolence with IM olanzapine. ( 7.2 ) Other Concomitant Drug Therapy: When using olanzapine in combination with lithium or valproate, refer to the Drug Interactions sections of the package insert for those products.
Zyprexa label (H2-Pharma LLC, February 11, 2026), warnings and precautionsMay elevate prolactin levels. ( 5.15 ) Use in Combination with Fluoxetine, Lithium or Valproate:
Source: FDA drug label (Zyprexa, NDA020592), H2-Pharma LLC, effective February 11, 2026 (SPL set b418946a-1ab4-4d89-a012-d94fc361a3c4), via openFDA
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
| Lithium | Olanzapine | |
|---|---|---|
| Labeled for | Bipolar disorder | Schizophrenia, Bipolar disorder, Depression |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.104 per capsule 300 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