METHOTREXATE
(MTX)Standard Prescription
methotrexate__PO/SC weekly (__mg/m2/week) or (__mg/kg/week)
Dosages
Oncology:
Refer to individual treatment protocols.
Rheumatic diseases:
Crohn's Disease:
15 mg/m2 SC once a week (Max: 25 mg/dose)
Refer to individual treatment protocols.
Rheumatic diseases:
Juvenile Idiopathic Arthritis (JIA), juvenile dermatomyositis, vasculitis, uveitis, localized and generalized scleroderma
Initial: 10-15 mg/m2 /week PO/SC. (Doses may be increased to 20-30 mg/m2 /week in refractory disease)
or
0.3-0.6 mg/kg/week PO/SC (Max initial dose 15 mg/dose). Doses may be increased to 1.1 mg/kg/week in refractory disease (Max 30 mg/dose).
Crohn's Disease:
15 mg/m2 SC once a week (Max: 25 mg/dose)
Mechanism of Action
Immune suppressant; antimetabolite (antifolate); disease modifying antirheumatic drug (DMARD)
Forms Supplied
tablet: 2.5 mg, 10 mg tablets
injection (25 mg/mL): 20 mL, 40 mL, 100 mL vials
injection for IT use (10 mg/mL): 2 mL vial
injection (25 mg/mL): 20 mL, 40 mL, 100 mL vials
injection for IT use (10 mg/mL): 2 mL vial
Comments
Adverse effects include mucositis, GI upset, alopecia myelosuppression, hepatotoxicity, pneumonitis (rare), and photosensitivity.
Folic acid 1 mg/day or 5 mg once or twice weekly (except on the day of methotrexate) may reduce mucosal and GI toxicities.
Used in Crohn's disease when azathioprine or mercaptopurine are ineffective or not tolerated.
Folic acid 1 mg/day or 5 mg once or twice weekly (except on the day of methotrexate) may reduce mucosal and GI toxicities.
SC administration may be preferred for doses > 15 mg/m2 or to reduce GI adverse effects.
IM injection is much more painful than SC and should be avoided.
RNs throughout the hospital may administer methotrexate SC for rheumatic or Crohn's diseases; chemotherapy certification is not required.
Note: concomitant use of methotrexate and NSAID is a standard of care for treating JIA.
Refer to Nursing Policies under "Cytotoxic Drugs" and the BCCH parenteral monograph for detailed information on safe handling, administration, etc.
References
138, 139, 384
Sandhu BK, Fell JME, Beattie RM, et al. Guidelines for the management of inflammatory bowel disease in children in the United Kingdom. JPGN. 2010;50:S1-S13.
Colman RJ et al. Methotrexate for the treatment of pediatric Crohn's disease: a systematic review and meta-analysis. Inflamm Bowel Dis 2018; 24: 2135-2141.
Colman RJ et al. Methotrexate for the treatment of pediatric Crohn's disease: a systematic review and meta-analysis. Inflamm Bowel Dis 2018; 24: 2135-2141.
Last Edited
2021-08-02 20:08:17