Cimetidine and Mirtazapine interaction
Cimetidine and Mirtazapine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Cimetidine label · effective 2026-01-01
…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.
From the Mirtazapine (REMERONSOLTAB) label · effective 2025-08-06
Intervention Decrease the dose of REMERON/REMERONSolTab if needed with concomitant cimetidine use.
Conversely, an increase in dosage of REMERON/REMERONSolTab may be needed if cimetidine is discontinued [see Dosage and Administration (2.5) ] .
Cimetidine: Dosage decrease may be needed when REMERON/REMERONSolTab is coadministered with cimetidine.
Examples phenytoin, carbamazepine, rifampin Strong CYP3A Inhibitors Clinical Impact The concomitant use of strong CYP3A inhibitors with REMERON/REMERONSolTab may increase the plasma concentration of mirtazapine [see Clinical Pharmacology (12.3) ] .
Intervention Decrease the dose of REMERON/REMERONSolTab if needed with concomitant strong CYP3A inhibitor use.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.