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Pronunciation ⬇

meth-o-TREX-ate

Classifications ⬆ ⬇

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

Pharmacologic Classification: antimetabolites

Indications ⬆ ⬇

IM: IM: IM:

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 (SJS), TOXIC EPIDERMAL NECROLYSIS (TEN), 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 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, Nordimet