What the FDA labels say about taking them together
Asenapine and thioridazine
Asenapine's FDA label of January 31, 2025 names thioridazine in its warnings and precautions section; thioridazine's label does not name asenapine itself but warns about its class (Atypical antipsychotics).
Check it at the source: the asenapine FDA label on DailyMed (effective January 31, 2025, Allergan, Inc.); the thioridazine FDA label on DailyMed (effective November 11, 2025, Mylan Institutional Inc.).
What does the asenapine label say about thioridazine?
Asenapine label, warnings and precautionsThe use of SAPHRIS should be avoided in combination with other drugs known to prolong QTc including Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class 3 antiarrhythmics (e.g., amiodarone, sotalol), antipsychotic medications (e.g., ziprasidone, chlorpromazine, thioridazine), and antibiotics (e.g., gatifloxacin, moxifloxacin).
Source: FDA drug label (Secuado, NDA212268), Noven Therapeutics, LLC, effective January 30, 2025 (SPL set 685eaf44-5944-4f38-afba-0a4fc0b3462b), via openFDA
Source: FDA drug label (SAPHRIS), NDA022117 (Abbvie), as published by Allergan, Inc., effective January 31, 2025 (SPL set 5429f134-839f-4ffc-9944-55f51238def8), via openFDA; the full label on DailyMed
What does the thioridazine label say about asenapine?
Thioridazine's label does not name asenapine itself; it warns about its class (Atypical antipsychotics):
Thioridazine label, boxed warningAnalyses of seventeen placebo-controlled trials (modal duration of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk of death in placebo-treated patients.
Thioridazine label, boxed warningDue to its potential for significant, possibly life threatening, proarrhythmic effects, thioridazine should be reserved for use in the treatment of schizophrenic patients who fail to show an acceptable response to adequate courses of treatment with other antipsychotic drugs, either because of insufficient effectiveness or the inability to achieve an effective dose due to intolerable adverse effects from those drugs (see WARNINGS , CONTRAINDICATIONS , and INDICATIONS ).
Source: FDA drug label (Thioridazine Hydrochloride), Mylan Institutional Inc., effective November 11, 2025 (SPL set 52fea941-0b47-41c1-b00d-f88150e8ab93), 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
| Asenapine | Thioridazine | |
|---|---|---|
| Labeled for | Schizophrenia, Bipolar disorder | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $2.63 per tablet 10 mg tablet sl | $0.571 per tablet 25 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