section name header

Pronunciation

meth-o-TREX-ate

Classifications

Therapeutic Classification: antineoplastics, antirheumatics (DMARDs), Immunosuppressant agents

Pharmacologic Classification: antimetabolites

Indications

High Alert


Action

  • Interferes with folic acid metabolism. Result is inhibition of DNA synthesis and cell reproduction (cell-cycle S-phase–specific).
  • Also has immunosuppressive activity.
Therapeutic effects:
  • Death of rapidly replicating cells, particularly malignant ones, and immunosuppression.

Pharmacokinetics

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 (23–95%) and dose-dependent.

Metabolism/Excretion: Excreted mostly unchanged by the kidneys.

Half-Life: Low dose: 3–10 hr; high dose: 8–15 hr ( in renal impairment).

Time/Action Profile

(effects on blood counts)

ROUTEONSETPEAKDURATION
PO, IM, IV4–7 days7–14 days21 days
SUBQunknownunknownunknown



Contraind./Precautions

Contraindicated in:

Use Cautiously in:

Adv. Reactions/Side Effects

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

Metab: hyperuricemia

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

Interactions

Drug-drug:

Drug-Natural Products:

Route/Dosage

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

Availability

(Generic available)

Assessment

Lab Test Considerations:

Toxicity and Overdose:

Implementation

IV Administration:

Patient/Family Teaching

Evaluation/Desired Outcomes

US Brand Names

Jylamvo, Otrexup, Rasuvo, Rheumatrex, Trexall, Xatmep

Canadian Brand Names

Metoject

Code

NDC Code