What the FDA labels say about taking them together
Dofetilide and quinine
Quinine's FDA label of November 9, 2023 names dofetilide in its warnings and precautions (prescription label) section; the dofetilide label PlainMeds reads does not name quinine. The quinine label: “Quinine sulfate is not recommended for use with other drugs known to cause QT prolongation, including Class IA antiarrhythmic agents, and Class III antiarrhythmic agents.”
Check it at the source: the dofetilide FDA label on DailyMed (effective April 21, 2026, Pfizer Laboratories Div Pfizer Inc); the quinine FDA label on DailyMed (effective November 9, 2023).
What does the dofetilide label say about quinine?
Dofetilide's label (effective April 21, 2026) does not name quinine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Tikosyn), Pfizer Laboratories Div Pfizer Inc, effective April 21, 2026 (SPL set 02438044-d6a3-49e9-a1ac-3aad21ef2c8c), via openFDA; the full label on DailyMed
What does the quinine label say about dofetilide?
Quinine label, warnings and precautions (prescription label)Quinine sulfate is not recommended for use with other drugs known to cause QT prolongation, including Class IA antiarrhythmic agents (e.g., quinidine, procainamide, disopyramide), and Class III antiarrhythmic agents (e.g., amiodarone, sotalol, dofetilide).
Source: FDA drug label (Chininum sulphuricum), Boiron, effective November 9, 2023 (SPL set 33885950-2a55-11e7-8288-424c58303031), 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
| Dofetilide | Quinine | |
|---|---|---|
| Labeled for | Atrial fibrillation | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.203 per capsule 125 mcg capsule | $0.698 per capsule 324 mg capsule |
| 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