What the FDA labels say about taking them together
Lidocaine and quinidine
Lidocaine's FDA label (Lidocaine Hydrochloride And Dextrose) of February 20, 2026 names quinidine in its drug interactions section; the quinidine label PlainMeds reads does not name lidocaine.
Check it at the source: the lidocaine FDA label on DailyMed (effective May 13, 2024, Fresenius Kabi USA, LLC); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the lidocaine label say about quinidine?
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 quinidine label say about lidocaine?
Quinidine's label (effective February 1, 2018) does not name lidocaine 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
| Lidocaine | Quinidine | |
|---|---|---|
| Labeled for | Pain | Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.154 per gram 5% ointment | $4.92 per tablet 324 mg tablet |
| 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