What the FDA labels say about taking them together
Quinidine and tramadol
Tramadol's FDA label of March 5, 2026 names quinidine in its drug interactions section; the quinidine label PlainMeds reads does not name tramadol. The tramadol label: “The concomitant use of tramadol hydrochloride extended-release tablets and CYP2D6 inhibitors may result in an increase in the plasma concentration of tramadol and a decrease in the plasma concentration of M1 …”
Check it at the source: the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.); the tramadol FDA label on DailyMed (effective March 5, 2026, Lupin Pharmaceuticals, Inc.).
What does the quinidine label say about tramadol?
Quinidine's label (effective February 1, 2018) does not name tramadol 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 tramadol label say about quinidine?
Tramadol label, drug interactionsInhibitors of CYP2D6 Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP2D6 inhibitors may result in an increase in the plasma concentration of tramadol and a decrease in the plasma concentration of M1, particularly when an inhibitor is added after a stable dose of tramadol hydrochloride extended-release tablets is achieved. … patients at frequent intervals for adverse events including respiratory depression and sedation. Examples: Quinidine, fluoxetine, paroxetine and bupropion.
Tramadol label, warnings and precautionsRisks of Concomitant Use or Discontinuation of Cytochrome P450 2D6 Inhibitors The concomitant use of tramadol hydrochloride extended-release tablets with all cytochrome P450 2D6 inhibitors (e.g., amiodarone, quinidine) may result in an increase in tramadol plasma levels and a decrease in the levels of the active metabolite, M1.
Source: FDA drug label (Tramadol Hydrochloride Extended-Release, NDA022370), Trigen Laboratories, LLC, effective January 23, 2026 (SPL set c0bc7218-3fd0-4646-96f4-25355fc84aa9), via openFDA
Source: FDA drug label (TRAMADOL HYDROCHLORIDE), Lupin Pharmaceuticals, Inc., effective March 5, 2026 (SPL set 46bb9ae6-3ee8-463c-badb-c7a45a89b84b), 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 | Tramadol | |
|---|---|---|
| Labeled for | Atrial fibrillation | Pain |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $4.92 per tablet 324 mg tablet | $0.0248 per tablet 50 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