What the FDA labels say about taking them together
Pimavanserin and thioridazine
Pimavanserin's FDA label of June 18, 2026 names thioridazine in its warnings and precautions section; thioridazine's label does not name pimavanserin itself but warns about its class (Atypical antipsychotics). The pimavanserin label: “The use of NUPLAZID should be avoided in patients with known QT prolongation or in combination with other drugs known to prolong QT interval including Class 1A antiarrhythmics or Class 3 antiarrhythmics, certain …”
Check it at the source: the pimavanserin FDA label on DailyMed (effective June 18, 2026, Acadia Pharmaceuticals Inc.); the thioridazine FDA label on DailyMed (effective November 11, 2025, Mylan Institutional Inc.).
What does the pimavanserin label say about thioridazine?
Pimavanserin label, warnings and precautionsThe use of NUPLAZID should be avoided in patients with known QT prolongation or in combination with other drugs known to prolong QT interval including Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class 3 antiarrhythmics (e.g., amiodarone, sotalol), certain antipsychotic medications (e.g., ziprasidone, chlorpromazine, thioridazine), and certain antibiotics (e.g., gatifloxacin, moxifloxacin) [see Drug Interactions (7.1) ].
Source: FDA drug label (NUPLAZID), Acadia Pharmaceuticals Inc., effective June 18, 2026 (SPL set 1e6bea44-57d6-4bac-9328-46e1ee59f83b), via openFDA; the full label on DailyMed
What does the thioridazine label say about pimavanserin?
Thioridazine's label does not name pimavanserin 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
| Pimavanserin | Thioridazine | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $170.50 per capsule 34 mg capsule | $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