Therapeutic Classification: antineoplastics, antirheumatics (DMARDs), Immunosuppressant agents
Pharmacologic Classification: antimetabolites
High Alert
Absorption: Small doses are well absorbed from the GI tract. Larger doses incompletely absorbed.
Distribution: Actively transported across cell membranes, widely distributed. Does not reach therapeutic concentrations in the CSF. Absorption in children is variable (2395%) and dose-dependent.
Half-Life: Low dose: 310 hr; high dose: 815 hr (↑ in renal impairment).
(effects on blood counts)
ROUTE | ONSET | PEAK | DURATION |
---|---|---|---|
PO, IM, IV | 47 days | 714 days | 21 days |
SUBQ | unknown | unknown | unknown |
Contraindicated in:
Use Cautiously in:
Derm: alopecia, ERYTHEMA MULTIFORME, painful plaque erosions (during psoriasis treatment), photosensitivity, pruritus, rash, skin ulceration, soft tissue necrosis, STEVENS-JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS, urticaria
EENT: blurred vision, transient blindness
GI: anorexia, diarrhea, nausea, stomatitis, vomiting, GI PERFORATION, HEPATOTOXICITY
GU: nephropathy, ↓fertility, acute renal failure, menstrual abnormalities, oligospermia
Hemat: anemia, leukopenia, thrombocytopenia, APLASTIC ANEMIA
MS: hemiparesis, osteonecrosis, stress fracture
Neuro: arachnoiditis (IT use only), confusion, dizziness, drowsiness, dysarthria, headache, leukoencephalopathy, malaise, SEIZURES
Resp: INTERSTITIAL PNEUMONITIS
Misc: chills, fever, HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS), INFECTION, SECONDARY MALIGNANCY, tumor lysis syndrome
Drug-drug:
Drug-Natural Products:
Acute Lymphoblastic Leukemia
Meningeal Leukemia
Non-Hodgkin's Lymphoma
Osteosarcoma
Breast Cancer
Squamous Cell Carcinoma of Head and Neck
Gestational Trophoblastic Neoplasia
Mycosis Fungoides
Rheumatoid Arthritis
Polyarticular Juvenile Idiopathic Arthritis
Psoriasis
Lab Test Considerations:
Toxicity and Overdose:
Fatalities have occurred with chemotherapeutic agents. Before administering, clarify all ambiguous orders; double-check single, daily, and course-of-therapy dose limits; have second practitioner independently double-check original order, calculations, and infusion pump settings. Methotrexate for nononcologic use is given at a much lower dose and frequencyoften just once a wk. Do not confuse nononcologic dosing regimens with dosing regimens for cancer patients. Do not confuse methotrexate with metolazone or MTX Patch (lidocaine/menthol). Do not confuse Trexall with Paxil.
IV Administration:
NDC Code