ModerateMacrolides×Antimetabolites, folic acid analogues
Updated · Methodology
Mechanism
Antibiotics may affect methotrexate gut absorption. Low clinical significance at rheumatological methotrexate doses (5–25 mg weekly).
Symptoms
Mostly no changes. At high oncologic methotrexate doses: risk of rising levels with toxicity symptoms (stomatitis, diarrhoea, falling leukocyte count).
Management
At low rheumatological methotrexate doses, the combination is acceptable without adjustment. At high oncologic doses: avoid azithromycin; alternative antibiotics (a cephalosporin, nitrofurantoin for UTI).
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