What the FDA labels say about taking them together
Cimetidine and lidocaine
Cimetidine's FDA label of July 15, 2026 names lidocaine in its drug interactions section, and lidocaine's label names cimetidine too. The lidocaine label: “Monitor toxicity when coadministering lidocaine with cimetidine.”
Check it at the source: the cimetidine FDA label on DailyMed (effective July 15, 2026, Mylan Pharmaceuticals Inc.); the lidocaine FDA label on DailyMed (effective May 13, 2024, Fresenius Kabi USA, LLC).
What does the cimetidine label say about lidocaine?
Cimetidine label, drug interactionsDrug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs.
Source: FDA drug label (Cimetidine), Mylan Pharmaceuticals Inc., effective July 15, 2026 (SPL set 06c0a509-026f-44e0-9975-a94a8de51d43), via openFDA; the full label on DailyMed
What does the lidocaine label say about cimetidine?
Lidocaine Hydrochloride And Dextrose label (Baxter Healthcare Corporation, February 20, 2026), drug interactionsMonitor toxicity when coadministering lidocaine with cimetidine.
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
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
| Cimetidine | Lidocaine | |
|---|---|---|
| Labeled for | Acid reflux and ulcers | Pain |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.236 per tablet 300 mg tablet | $0.154 per gram 5% ointment |
| Shortage now | No current entry | In shortage |
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