What the FDA labels say about taking them together
Lidocaine and procainamide
Lidocaine's FDA label (Lidocaine Hydrochloride And Dextrose) of February 20, 2026 names procainamide in its drug interactions section, and procainamide's label names lidocaine too.
Check it at the source: the lidocaine FDA label on DailyMed (effective May 13, 2024, Fresenius Kabi USA, LLC); the procainamide FDA label on DailyMed (effective February 17, 2025, Caplin Steriles Limited).
What does the lidocaine label say about procainamide?
Lidocaine Hydrochloride And Dextrose label (Baxter Healthcare Corporation, February 20, 2026), drug interactionsWhen lidocaine is administered with other antiarrhythmic drugs such as amiodarone, phenytoin, procainamide, propranolol or quinidine, the cardiac effects may be additive or antagonistic and toxic effects may be additive.
Source: FDA drug label (Lidocaine Hydrochloride And Dextrose, NDA018461), Baxter Healthcare Corporation, effective February 20, 2026 (SPL set f21512ea-c7c3-4766-b976-b2c0b5616bf0), via openFDA
Source: FDA drug label (Xylocaine MPF), Fresenius Kabi USA, LLC, effective May 13, 2024 (SPL set d5e0d06f-ba1e-44d4-aa89-39d6c146dc23), via openFDA; the full label on DailyMed
What does the procainamide label say about lidocaine?
Procainamide label, warningsTherefore, use of procainamide should be considered only if discontinuation of digitalis, and therapy with potassium, lidocaine, or phenytoin are ineffective.
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
| Lidocaine | Procainamide | |
|---|---|---|
| Labeled for | Pain | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.154 per gram 5% ointment | n/a |
| Shortage now | In shortage | 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