What the FDA labels say about taking them together
Cimetidine and protriptyline
Protriptyline's FDA label of July 25, 2023 names cimetidine in its drug interactions section; cimetidine's label does not name protriptyline itself but warns about its class (Tricyclic antidepressants). The protriptyline label: “Cimetidine is reported to reduce hepatic metabolism of certain tricyclic antidepressants, thereby delaying elimination and increasing steady-state concentrations of these drugs.”
Check it at the source: the cimetidine FDA label on DailyMed (effective July 15, 2026, Mylan Pharmaceuticals Inc.); the protriptyline FDA label on DailyMed (effective July 25, 2023, Epic Pharma, LLC).
What does the cimetidine label say about protriptyline?
Cimetidine's label does not name protriptyline itself; it warns about its class (Tricyclic antidepressants):
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 protriptyline label say about cimetidine?
Protriptyline label, drug interactionsCimetidine is reported to reduce hepatic metabolism of certain tricyclic antidepressants, thereby delaying elimination and increasing steady-state concentrations of these drugs.
Source: FDA drug label (Protriptyline Hydrochloride), Epic Pharma, LLC, effective July 25, 2023 (SPL set c6c7c39e-e510-4f4a-bf7a-926f0e075d3a), 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 | Protriptyline | |
|---|---|---|
| Labeled for | Acid reflux and ulcers | Depression |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.236 per tablet 300 mg tablet | $2.71 per tablet 10 mg tablet |
| 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