Table 1.
Common drug-drug interactions with MTX
| DRUGS* | ADVERSE REACTION | SUPPORTING EVIDENCE |
|---|---|---|
| TMP-SMX | Bone marrow suppression, renal toxicity | ≥ 17 case reports and 1 retrospective case-control study |
| Penicillins and cephalosporins (eg, amoxicillin, cephalexin) | Bone marrow suppression | ≥ 5 case reports and multiple interaction studies |
| NSAIDs (eg, high-dose ASA, indomethacin, ibuprofen) | Bone marrow suppression | ≥ 30 case reports, 2 retrospective observational studies, and multiple interaction studies |
ASA—acetylsalicylic acid, MTX—methotrexate, NSAIDs—nonsteroidal anti-inflammatory drugs, TMP-SMX—trimethoprim-sulfamethoxazole.
*
Rare drug-drug interactions have also been reported with MTX and quinolones, macrolides, retinoids, proton pump inhibitors, isoniazid, ranitidine, probenecid, and theophylline; however, the reliability and clinical importance of these potential interactions are substantially uncertain.