What the FDA labels say about taking them together
Clarithromycin and quinidine
Clarithromycin's FDA label of April 9, 2026 names quinidine in its drug interactions section; the quinidine label PlainMeds reads does not name clarithromycin. The clarithromycin label: “Disopyramide Quinidine Dofetilide Amiodarone Sotalol Procainamide Not Recommended Disopyramide, Quinidine:”
Check it at the source: the clarithromycin FDA label on DailyMed (effective April 9, 2026, Solaris Pharma Corporation); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the clarithromycin label say about quinidine?
Clarithromycin label, drug interactionsDisopyramide Quinidine Dofetilide Amiodarone Sotalol Procainamide Not Recommended Disopyramide, Quinidine:
Clarithromycin label, warnings and precautionsAvoid clarithromycin in the following patients: patients with known prolongation of the QT interval, ventricular cardiac arrhythmia, including torsades de pointes patients receiving drugs known to prolong the QT interval [see also Contraindications (4.2) ] patients with ongoing proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia and in patients receiving Class IA (e.g., quinidine, procainamide, disopyramide) or Class III (e.g., dofetilide, amiodarone, sotalol) antiarrhythmic agents.
Source: FDA drug label (Clarithromycin), Solaris Pharma Corporation, effective April 9, 2026 (SPL set 4d42821d-ce7a-7d64-e063-6294a90a0875), via openFDA; the full label on DailyMed
What does the quinidine label say about clarithromycin?
Quinidine's label (effective February 1, 2018) does not name clarithromycin 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
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
| Clarithromycin | Quinidine | |
|---|---|---|
| Labeled for | Bacterial infections, Acid reflux and ulcers | Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.466 per tablet 500 mg tablet | $4.92 per tablet 324 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