What the FDA labels say about taking them together
Macimorelin and procainamide
Macimorelin's FDA label of February 18, 2026 names procainamide in its drug interactions section; the procainamide label PlainMeds reads does not name macimorelin. The macimorelin label: “DRUG INTERACTIONS 7.1 Drugs that Prolong QT Interval Co-administration of MACRILEN with drugs that prolong the QT interval may lead to development of torsade de pointes-type ventricular tachycardia.”
Check it at the source: the macimorelin FDA label on DailyMed (effective February 18, 2026, Aeterna Zentaris GmbH); the procainamide FDA label on DailyMed (effective February 17, 2025, Caplin Steriles Limited).
What does the macimorelin label say about procainamide?
Macimorelin label, drug interactionsDRUG INTERACTIONS 7.1 Drugs that Prolong QT Interval Co-administration of MACRILEN with drugs that prolong the QT interval (such as antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications or any other medications known to prolong the QT interval) may lead to development of torsade de pointes-type ventricular tachycardia.
Source: FDA drug label (Macrilen), Aeterna Zentaris GmbH, effective February 18, 2026 (SPL set aeb30f1a-4815-47ae-a2cb-b6b4e26372e1), via openFDA; the full label on DailyMed
What does the procainamide label say about macimorelin?
Procainamide's label (effective February 17, 2025) does not name macimorelin in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Procainamide Hydrochloride), Caplin Steriles Limited, effective February 17, 2025 (SPL set fcaa5e9a-3c8a-4796-aa87-626268b6cf60), 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
| Macimorelin | Procainamide | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | n/a |
| 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