Famotidine has 22 known drug interactions based on U.S. FDA drug labeling data. Of these, 5 are contraindicated combinations that should be avoided entirely. 12 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Cefditoren, Dasatinib, Delavirdine Mesylate. Patients taking Famotidine should inform their healthcare provider of all current medications — including over-the-counter drugs and supplements — to avoid potentially harmful combinations. Data sourced from OpenFDA and the NIH National Library of Medicine.
- Total
- 22
- Contraindicated
- 5
- Major
- 12
- Moderate
- 2
Contraindicated (5)
- Famotidine + Cefditoren— Famotidine reduces gastric acidity and may significantly reduce cefditoren absorption, leading to loss of efficacy.
- Famotidine + Dasatinib— Famotidine reduces gastric acidity and may significantly reduce dasatinib absorption, leading to loss of efficacy.
- Famotidine + Delavirdine Mesylate— Famotidine reduces gastric acidity and may significantly reduce delavirdine mesylate absorption, leading to loss of effi…
- Famotidine + Fosamprenavir— Famotidine reduces gastric acidity and may significantly reduce fosamprenavir absorption, leading to loss of efficacy.
- Famotidine + Tizanidine— Famotidine is a weak CYP1A2 inhibitor and may substantially increase tizanidine blood concentrations, resulting in hypot…
Major (12)
- Famotidine + Atazanavir— Famotidine reduces gastric acidity and may significantly reduce atazanavir absorption. See prescribing information for a…
- Famotidine + Dichlorphenamide— Concomitant use is not recommended as dichlorphenamide inhibits OAT1 transporters, increasing famotidine plasma exposure…
- Famotidine + Erlotinib— Famotidine reduces gastric acidity and may significantly reduce erlotinib absorption. See prescribing information for ad…
- Famotidine + Itraconazole— Famotidine reduces gastric acidity and may significantly reduce itraconazole absorption. See prescribing information for…
- Famotidine + Ketoconazole— Famotidine reduces gastric acidity and may significantly reduce ketoconazole absorption. See prescribing information for…
- Famotidine + Ledipasvir And Sofosbuvir— Famotidine reduces gastric acidity and may significantly reduce ledipasvir/sofosbuvir absorption. See prescribing inform…
- Famotidine + Nilotinib— Famotidine reduces gastric acidity and may significantly reduce nilotinib absorption. See prescribing information for ad…
- Famotidine + Rilpivirine— Famotidine reduces gastric acidity and may significantly reduce rilpivirine absorption. See prescribing information for …
- Famotidine + Tizanidine Hydrochloride— Concomitant use should be avoided due to potential interactions. If clinically necessary, initiate with 2 mg and titrate…
- Famotidine + Tizanidne Hydrochloride— Should be avoided due to CYP1A2 inhibition. If necessary, initiate tizanidine at 2 mg and titrate cautiously; monitor fo…
- Famotidine + Warfarin— CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring
- Famotidine + Warfarin Sodium— CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring.
Moderate (2)
- Famotidine + Acalabrutinib— H2-receptor antagonist may decrease acalabrutinib concentrations. Take acalabrutinib 2 hours before famotidine dosing.
- Famotidine + Thalidomide— H2 blocker famotidine may cause additive bradycardic effect with thalidomide and should be used with caution.