Methotrexate Treatment Guidelines

Indications and Dosage

The American Academy of Dermatology recommends methotrexate for off-label use in atopic dermatitis, with a dosage of 10-25 mg/week 1, 2
The European Crohn's and Colitis Organisation suggests methotrexate for inflammatory bowel disease, with a dosage of 25 mg/week intramuscularly for induction and 15 mg/week for maintenance 3, 4
The American College of Rheumatology recommends methotrexate for rheumatoid arthritis, with a starting dose of 10-15 mg/week orally and dose escalation of 5 mg every 2-4 weeks up to 20-30 mg/week based on clinical response and tolerability 5, 6

The American Academy of Dermatology recommends complete blood count (CBC) with differential every 2-4 weeks for the first few months, then every 1-3 months depending on dose adjustments and previous results 6, 7
The British Society of Gastroenterology suggests liver function tests (AST, ALT, albumin, bilirubin) monthly initially, then every 2-3 months based on dose adjustments and previous results 6, 8
The National Kidney Foundation recommends renal function (creatinine, eGFR) monitoring every 2-3 months 6

The British Journal of Dermatology reports that gastrointestinal symptoms (nausea, vomiting, diarrhea, stomatitis) occur in up to 25% of patients 8
The BMJ warns of hepatotoxicity, which may lead to fibrosis and cirrhosis with long-term use 9, 6
The Gut journal notes that pulmonary toxicity (pneumonitis, fibrosis) is a rare but serious side effect 4

The Annals of the Rheumatic Diseases recommend folic acid supplementation of at least 5 mg per week to reduce gastrointestinal and liver toxicity without reducing efficacy 5
The British Journal of Dermatology suggests dose adjustments for renal impairment, with eGFR >90 mL/min requiring normal dose, eGFR 20-50 mL/min requiring half dose, and eGFR <20 mL/min requiring avoidance of methotrexate 8
The Journal of the American Academy of Dermatology recommends alcohol limitation due to increased risk of hepatotoxicity 6

The BMJ lists absolute contraindications, including pregnancy and breastfeeding, significant hepatic damage or cirrhosis, severe renal impairment (eGFR <20 mL/min), and bone marrow suppression (anemia, leukopenia, thrombocytopenia) 9, 6
The Journal of the American Academy of Dermatology recommends that women wait at least 3 months after discontinuing methotrexate before attempting to conceive, and men wait 3 months after discontinuation before attempting to father children 10

The BMJ reports that methotrexate is effective for extensive chronic plaque psoriasis, pustular psoriasis, and psoriatic erythroderma 9
The Gut journal notes that methotrexate is effective for inducing remission and preventing relapse in Crohn's disease, with 39% of steroid-dependent patients able to withdraw steroids and enter remission (vs. 19% with placebo) 4