What the FDA labels say about taking them together
Disopyramide and haloperidol
Haloperidol's FDA label (Haloperidol Decanoate) of February 19, 2025 names disopyramide in its drug interactions section; the disopyramide label PlainMeds reads does not name haloperidol. The haloperidol label: “Pharmacodynamic Interactions Since QTc interval-prolongation has been observed during haloperidol treatment, caution is advised when prescribing to a patient with QT-prolongation conditions or to patients receiving …”
Check it at the source: the disopyramide FDA label on DailyMed (effective August 24, 2026, Pfizer Laboratories Div Pfizer Inc); the haloperidol FDA label on DailyMed (effective April 23, 2026, PD-Rx Pharmaceuticals, Inc.).
What does the disopyramide label say about haloperidol?
Disopyramide's label (effective August 24, 2026) does not name haloperidol in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Norpace), Pfizer Laboratories Div Pfizer Inc, effective August 24, 2026 (SPL set e2aa1642-d262-4520-bc6a-9fd3ad795677), via openFDA; the full label on DailyMed
What does the haloperidol label say about disopyramide?
Haloperidol Decanoate label (Patriot Pharmaceuticals LLC, February 19, 2025), drug interactionsPharmacodynamic Interactions Since QTc interval-prolongation has been observed during haloperidol treatment, caution is advised when prescribing to a patient with QT-prolongation conditions or to patients receiving medications known to prolong the QTc-interval (see WARNINGS, Cardiovascular Effects ). Examples include (but are not limited to): Class 1A antiarrhythmics (e.g., procainamide, quinidine, disopyramide);
Source: FDA drug label (Haloperidol Decanoate, NDA018701), Patriot Pharmaceuticals LLC, effective February 19, 2025 (SPL set 9f0f42a8-5f7c-4be7-93ef-3ec225502cc6), via openFDA
Source: FDA drug label (Haloperidol), PD-Rx Pharmaceuticals, Inc., effective April 23, 2026 (SPL set 533b0b4c-cbd6-4ec0-a333-8b04b5b43a1d), 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
| Disopyramide | Haloperidol | |
|---|---|---|
| Labeled for | n/a | Schizophrenia |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.801 per capsule 100 mg capsule | $15.60 per mL 100 mg/mL vial |
| Shortage now | A presentation being discontinued | A presentation being discontinued |
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