What the FDA labels say about taking them together
Carbamazepine and cimetidine
Carbamazepine's FDA label of August 20, 2026 names cimetidine in its drug interactions section; the cimetidine label PlainMeds reads does not name carbamazepine. The carbamazepine label: “Drugs that have been shown, or would be expected, to increase plasma carbamazepine levels include aprepitant, cimetidine, ciprofloxacin, danazol, diltiazem, macrolides, fluoxetine, fluvoxamine, trazodone, omeprazole …”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the cimetidine FDA label on DailyMed (effective July 15, 2026, Mylan Pharmaceuticals Inc.).
What does the carbamazepine label say about cimetidine?
Carbamazepine label, drug interactionsDrugs that have been shown, or would be expected, to increase plasma carbamazepine levels include aprepitant, cimetidine, ciprofloxacin, danazol, diltiazem, macrolides (e.g., erythromycin, clarithromycin), fluoxetine, fluvoxamine, trazodone, omeprazole, oxybutynin, isoniazid, niacinamide (nicotinamide), azoles (e.g., ketaconazole, itraconazole, fluconazole, voriconazole), acetazolamide, verapamil, ticlopidine, grapefruit juice, and protease inhibitors.
Carbatrol label (Takeda Pharmaceuticals America, Inc., August 17, 2026), drug interactionsAcetazolamide, aprepitant, azole antifungals (e.g., ketoconazole, itraconazole, fluconazole, voriconazole), cimetidine, ciprofloxacin, clarithromycin, dalfopristin, danazol, dantrolene, delavirdine, diltiazem, erythromycin, fluoxetine, fluvoxamine, grapefruit juice, ibuprofen, isoniazid, loratadine, macrolides, nefazodone, niacinamide, nicotinamide, olanzapine, omeprazole, oxybutynin, protease inhibitors, propoxyphene, quinine, quinupristin, ticlopidine, troleandomycin, valproate, verapamil, zileuton.
Equetro label (Validus Pharmaceuticals LLC, August 19, 2025), drug interactionsThe following drugs are CYP3A4 inhibitors: Acetazolamide, aprepitant, azole antifungals (e.g., ketoconazole, itraconazole, fluconazole, voriconazole ), cimetidine, ciprofloxacin, clarithromycin, dalfopristin, danazol, dantrolene, delavirdine, diltiazem, erythromycin, fluoxetine, fluvoxamine, grapefruit juice, ibuprofen, isoniazid, loratadine, nefazodone, niacinamide, nicotinamide, olanzapine, omeprazole, oxybutynin, quinine, quinupristin, ticlopidine, troleandomycin, valproate, verapamil, zileuton.
Source: FDA drug label (Carbatrol, NDA020712), Takeda Pharmaceuticals America, Inc., effective August 17, 2026 (SPL set bc03e499-5bac-4293-bff4-6864153a624d), via openFDA
Source: FDA drug label (Equetro, NDA021710), Validus Pharmaceuticals LLC, effective August 19, 2025 (SPL set be478f3c-40f6-47cc-8ab9-f420a9372b1c), via openFDA
Source: FDA drug label (Tegretol), Novartis Pharmaceuticals Corporation, effective August 20, 2026 (SPL set 8d409411-aa9f-4f3a-a52c-fbcb0c3ec053), via openFDA; the full label on DailyMed
What does the cimetidine label say about carbamazepine?
Cimetidine's label (effective July 15, 2026) does not name carbamazepine in these sections. A label lists what its studies and reports found; it is not a complete list.
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
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
| Carbamazepine | Cimetidine | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Acid reflux and ulcers |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $0.236 per tablet 300 mg tablet |
| Shortage now | A presentation being discontinued | 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