Methotrexate is prescribed for autoimmune conditions, certain cancers, and ectopic pregnancies, with a unique dosage of once weekly to prevent toxicity. Understanding the correct usage of methotrexate is crucial for its effectiveness and safety. Withhold, dose reduce, or discontinue Methotrexate Tablets taking into account the importance of Methotrexate Tablet treatment in the context of the severity of the disease being treated, the severity of the adverse drug reaction, and availability of alternative therapy [see Dosage and Administration (2.6)]. Initial Dosing Strategy A test dose of 2.5-5 mg is recommended before starting full therapy, especially in patients with impaired kidney function or other significant comorbidities 3, 4 For rheumatoid arthritis, the recommended starting dose is 7.5 mg once weekly, administered intramuscularly with escalation to achieve optimal response 2 For psoriasis, methotrexate is typically administered in. Methotrexate Dosing and Treatment Regimen for Rheumatoid Arthritis For patients with rheumatoid arthritis, methotrexate should be started at 15 mg/week orally, with escalation by 5 mg every 2-4 weeks up to 25-30 mg/week or the highest tolerable dose, with consideration of switching to subcutaneous administration if response is inadequate. 1, 2 Detailed Methotrexate dosage information for adults and children. Includes dosages for Rheumatoid Arthritis, Psoriasis, Breast Cancer and more; plus renal, liver and dialysis adjustments. NHS medicines information on dosage for methotrexate, how to take it and what to do if you miss a dose or take too much. Description Methotrexate tablet is used alone or together with other medicines to treat several types of cancer, such as breast, head and neck, lung, blood (eg, acute lymphoblastic leukemia or ALL), bone, lymph node (eg, mycosis fungoides, relapsed or refractory non-Hodgkin lymphoma), or uterus cancer. Trexall: May give weekly dose divided as 2.5 mg PO q12hr for 3 sequential doses Otrexup (SC): If used as initial therapy, start a lowest available dose (ie, 10 mg SC weekly) Rasuvo or RediTrex (SC): 10-25 mg SC once weekly Administer folic acid or folinic acid to reduce the risk of methotrexate adverse reactions Dosage Modifications Renal. Methotrexate Calculation: Your Essential Dosage Calculator Methotrexate Dosage Calculator Calculate the appropriate Methotrexate dose based on patient's Body Surface Area (BSA) and target dose per square meter. Methotrexate treats certain leukemias and lymphomas, mycosis fungoides, rheumatoid arthritis, polyarticular juvenile idiopathic arthritis in children, and severe psoriasis in adults. Learn about side effects, interactions, and indications.