What the FDA labels say about taking them together
Olanzapine and tetrabenazine
Tetrabenazine's FDA label of November 29, 2019 names olanzapine in its drug interactions section; the olanzapine labels PlainMeds reads (3) do not name tetrabenazine. The tetrabenazine label: “The risk for Parkinsonism, NMS, and akathisia may be increased by concomitant use of tetrabenazine tablets and dopamine antagonists or antipsychotics.”
Check it at the source: the olanzapine FDA label on DailyMed (effective March 5, 2026, Macleods Pharmaceuticals Limited); the tetrabenazine FDA label on DailyMed (effective November 29, 2019, Oceanside Pharmaceuticals).
What does the olanzapine label say about tetrabenazine?
Olanzapine's label (effective March 5, 2026) and its 2 other brand-application labels do not name tetrabenazine in these sections. A label lists what its studies and reports found; it is not a complete list.
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
What does the tetrabenazine label say about olanzapine?
Tetrabenazine label, drug interactionsThe risk for Parkinsonism, NMS, and akathisia may be increased by concomitant use of tetrabenazine tablets and dopamine antagonists or antipsychotics (e.g., chlorpromazine, haloperidol, olanzapine, risperidone, thioridazine, ziprasidone) [see Warnings and Precautions ( 5.4 , 5.5 , 5.6 )].
Source: FDA drug label (tetrabenazine), NDA021894 (Bausch), as published by Oceanside Pharmaceuticals, effective November 29, 2019 (SPL set 5867189c-17bd-4e70-a079-c4730f9950d1), 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
| Olanzapine | Tetrabenazine | |
|---|---|---|
| Labeled for | Schizophrenia, Bipolar disorder, Depression | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.147 per tablet 20 mg tablet | $0.702 per tablet 12.5 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