What the FDA labels say about taking them together
Quinidine and trimipramine
Trimipramine's FDA label of March 17, 2026 names quinidine in its drug interactions section; the quinidine label PlainMeds reads does not name trimipramine.
Check it at the source: the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.); the trimipramine FDA label on DailyMed (effective March 17, 2026, Breckenridge Pharmaceutical, Inc.).
What does the quinidine label say about trimipramine?
Quinidine's label (effective February 1, 2018) does not name trimipramine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Quinidine Gluconate), Sun Pharmaceutical Industries, Inc., effective February 1, 2018 (SPL set 5023f053-fcc4-4c2c-aa59-9ec198ad185e), via openFDA; the full label on DailyMed
What does the trimipramine label say about quinidine?
Trimipramine label, drug interactionsThe drugs that inhibit cytochrome P450 2D6 include some that are not metabolized by the enzyme (quinidine; cimetidine) and many that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics propafenone and flecainide).
Source: FDA drug label (Trimipramine), Breckenridge Pharmaceutical, Inc., effective March 17, 2026 (SPL set 4f31df66-7dc2-1f04-e054-00144ff88e88), 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
| Quinidine | Trimipramine | |
|---|---|---|
| Labeled for | Atrial fibrillation | Depression |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $4.92 per tablet 324 mg tablet | 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