Methotrexate Toxicity and Monitoring

Established Toxicities

The American Academy of Dermatology recognizes hematologic toxicity, including pancytopenia, thrombocytopenia, leukopenia, and myelosuppression, as a well-established toxicity of methotrexate 1, 2, 5, 7
The British Association of Dermatologists acknowledges hepatotoxicity, including liver fibrosis and cirrhosis with cumulative dosing, as a known adverse effect of methotrexate 1, 2, 5, 7
Nephrotoxicity, including acute kidney injury and potential chronic renal impairment, is a recognized toxicity of methotrexate, particularly with high-dose therapy 7
Pulmonary toxicity, including pneumonitis, is a known adverse effect of methotrexate 4, 6
Gastrointestinal effects, such as mucositis, nausea, vomiting, and stomatitis, are common toxicities associated with methotrexate 4, 6

The American Academy of Dermatology recommends monitoring complete blood count with differential for patients on methotrexate therapy 2
The British Association of Dermatologists suggests monitoring liver function tests, including AST, ALT, albumin, and bilirubin, for patients on methotrexate 3
Renal function, including creatinine and calculated GFR, should be monitored in patients on methotrexate, as recommended by the American Academy of Dermatology and British Association of Dermatologists 2
The American Academy of Dermatology and British Association of Dermatologists do not recommend routine monitoring of serum sodium or electrolyte levels in patients on methotrexate 1, 4, 7