What the FDA labels say about taking them together
Levofloxacin and procainamide
Levofloxacin's FDA label of July 10, 2024 names procainamide in its warnings and precautions section; the procainamide label PlainMeds reads does not name levofloxacin. The levofloxacin label: “… with uncorrected hypokalemia, and patients receiving Class IA (quinidine, procainamide), or Class III (amiodarone, sotalol) antiarrhythmic agents.”
Check it at the source: the levofloxacin FDA label on DailyMed (effective July 10, 2024, Lupin Pharmaceuticals, Inc.); the procainamide FDA label on DailyMed (effective February 17, 2025, Caplin Steriles Limited).
What does the levofloxacin label say about procainamide?
Levofloxacin label, warnings and precautionsLevofloxacin should be avoided in patients with known prolongation of the QT interval, patients with uncorrected hypokalemia, and patients receiving Class IA (quinidine, procainamide), or Class III (amiodarone, sotalol) antiarrhythmic agents.
Source: FDA drug label (Levofloxacin), Lupin Pharmaceuticals, Inc., effective July 10, 2024 (SPL set 4be13bd5-0c39-43c3-9232-b1226ccd4dbc), via openFDA; the full label on DailyMed
What does the procainamide label say about levofloxacin?
Procainamide's label (effective February 17, 2025) does not name levofloxacin 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
| Levofloxacin | Procainamide | |
|---|---|---|
| Labeled for | Bacterial infections, Urinary tract infections | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.259 per tablet 750 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