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Pharmacologic class: Antimetabolite
Therapeutic class: Antineoplastic
Pregnancy risk category D
FDA Box Warning
• Drug may cause severe and even life-threatening adverse effects. Administer under supervision of physician experienced in using drug to treat sickle cell anemia.
• Drug damages genes, chromosomes, and DNA and may be carcinogenic. Secondary leukemias have occurred in patients receiving it as long-term therapy for myeloproliferative disorders. Prescriber and patient must carefully weigh potential benefits against undefined risk of secondary cancers.
Unknown. May inhibit enzyme necessary for DNA synthesis without disrupting RNA or protein synthesis.
Capsules: 200 mg, 300 mg, 400 mg, 500 mg
Indications and dosages
➣ Head and neck cancer; ovarian cancer; malignant melanoma
Adults: 60 to 80 mg/kg (2 to 3 g/m2) P.O. as a single daily dose q 3 days, or 20 to 30 mg/kg/day P.O. as a single dose. Begin therapy 7 days before radiation.
➣ Resistant chronic myelogenous leukemia
Adults: 20 to 30 mg/kg/day P.O. in one or two divided doses
➣ Sickle cell anemia
Adults and children: 15 mg/kg/day P.O. as a single dose. May increase by 5 mg/kg/day P.O. q 12 weeks, up to 35 mg/kg/day.
• Human immunodeficiency virus
• Hypersensitivity to drug or tartrazine
• Bone marrow depression
• Severe anemia or thrombocytopenia
Use cautiously in:
• renal or hepatic impairment
• obese patients
• females of childbearing age
• elderly patients.
• Provide frequent mouth care.
CNS: drowsiness, malaise, confusion, dizziness, headache
GI: nausea, vomiting, diarrhea, constipation, stomatitis, anorexia
GU: dysuria, hyperuricemia, infertility, renal tubular dysfunction
Hematologic: anemia, megaloblastosis, leukopenia, thrombocytopenia, bone marrow depression
Skin: alopecia, erythema, pruritus, rash, urticaria, exacerbation of post-radiation erythema
Other: chills, fever
Drug-drug. Live-virus vaccines: decreased antibody response to vaccine, increased risk of adverse reactions
Myelosuppressants: additive bone marrow depression
Drug-diagnostic tests. Blood urea nitrogen, creatinine, uric acid: increased values
Hemoglobin, platelets, red blood cells, white blood cells: decreased values
Mean corpuscular volume: transient increase
• Assess CBC weekly.
• Closely monitor patient with renal or hepatic impairment. Check kidney and liver function tests often.
• Assess fluid status. Make sure patient drinks 10 to 12 glasses of water daily.
• Advise patient to mark dates for drug doses, diagnostic tests, and treatments on calendar.
☞ Instruct patient to immediately report easy bruising, bleeding, unusual tiredness, or yellowing of skin or eyes.
• Tell patient to report such adverse effects as appetite loss, nausea, vomiting, oral lesions, constipation, diarrhea, confusion, dizziness, headache, and rash.
• Instruct female patient to use barrier contraception.
• Tell patient he will undergo regular blood testing to monitor drug effects.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.