What the FDA labels say about taking them together
Arsenic trioxide and pimozide
Pimozide's FDA label of August 12, 2026 names arsenic trioxide in its drug interactions section; the arsenic trioxide labels PlainMeds reads (2) do not name pimozide. The pimozide label: “… sparfloxacin, gatifloxacin, moxifloxacin, halofantrine, mefloquine, pentamidine, arsenic trioxide, levomethadyl acetate, dolasetron mesylate, probucol, tacrolimus, ziprasidone, or other drugs that have demonstrated QT …”
Check it at the source: the arsenic trioxide FDA label on DailyMed (effective July 23, 2021, Amneal Pharmaceuticals LLC); the pimozide FDA label on DailyMed (effective August 12, 2026, Par Health USA, LLC).
What does the arsenic trioxide label say about pimozide?
Arsenic trioxide's label (effective July 23, 2021) and its 1 other brand-application label do not name pimozide in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Arsenic Trioxide), Amneal Pharmaceuticals LLC, effective July 23, 2021 (SPL set 5845022e-8c01-451b-ae49-a28e58c5f845), via openFDA; the full label on DailyMed
What does the pimozide label say about arsenic trioxide?
Pimozide label, drug interactionsAccordingly, pimozide should not be given with dofetilide, sotalol, quinidine, other Class Ia and III anti-arrhythmics, mesoridazine, thioridazine, chlorpromazine, droperidol, sparfloxacin, gatifloxacin, moxifloxacin, halofantrine, mefloquine, pentamidine, arsenic trioxide, levomethadyl acetate, dolasetron mesylate, probucol, tacrolimus, ziprasidone, or other drugs that have demonstrated QT prolongation as one of their pharmacodynamic effects.
Source: FDA drug label (Pimozide), Par Health USA, LLC, effective August 12, 2026 (SPL set 70b079e2-a1f7-4a93-8685-d60a4d7c1280), 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
| Arsenic trioxide | Pimozide | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $1.23 per tablet 1 mg tablet |
| Shortage now | A presentation being discontinued | 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