MajorAntimetabolites, folic acid analogues×Proton pump inhibitors
Updated · Methodology
Mechanism
Proton pump inhibitors block the renal BCRP transporter, reducing methotrexate clearance. At high oncologic doses: risk of severe delayed toxicity.
Symptoms
Mouth ulcers (mucositis), nausea, diarrhoea, hair loss. Blood counts fall: leukocytes, platelets, erythrocytes. Severe cases: fatal pancytopenia, nephrotoxicity.
Management
At oncologic methotrexate doses, stop pantoprazole 5 days before and resume 5 days after dosing. Alternative: famotidine (H2-blocker, no BCRP effect). At low rheumatologic doses, pantoprazole is acceptable.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Methotrexate Sodium Tablets prescribing information (2016)– ; DailyMed setid 8f1260de-b60c-4f0e-8af6-0e957b0a281b
- AEMPS: Ficha técnica: Metotrexato (nº registro 78632), sección 4.5 (2024)– AEMPS, CIMA, nº registro 78632, revisión 11/2024, sección 4.5
- AEMPS: Ficha técnica: Pantoprazol (nº registro 68076), sección 4.5 (2021)– AEMPS, CIMA, nº registro 68076, revisión 10/2021, sección 4.5