TEMOZOLOMIDE

TEMOZOLOMIDE
(tem-o-zol'o-mide)
Temodar
Classifications: antineoplastic; alkylating agent;
Therapeutic: antineoplastic
Prototype: Cyclophosphamide
Pregnancy Category: D

Availability

5 mg, 20 mg, 100 mg, 140 mg, 180 mg, 250 mg capsules

Action

Cytotoxic agent with alkylating properties structurally similar to dacarbazine. Effects are cell cycle nonspecific. Interferes with purine (e.g., guanine) metabolism and thus protein synthesis in rapidly proliferating cells.

Therapeutic Effect

Effectiveness is indicated by objective evidence of tumor regression.

Uses

Adult patients with refractory anaplastic astrocytoma, glioblastoma multiforme with radiotherapy.

Contraindications

Hypersensitivity to temozolomide, DTIC, or dacarbazine; severe bone marrow suppression; children <3 y; pregnancy (category D), lactation.

Cautious Use

Bacterial or viral infection; older adults; severe hepatic or renal impairment; myelosuppression; prior radiotherapy or chemotherapy.

Route & Dosage

Astrocytoma
Adult: PO 150 mg/m² daily for 5 consecutive days per 28 d treatment cycle; subsequent doses are based on absolute neutrophil count on day 21 or at least 48 h before next scheduled cycle (see prescribing information for dosage adjustments based on neutrophil count)

Glioblastoma Multiforme
Adult: PO 75 mg/m² daily for 42 d with focal radiotherapy; after 4 wk, maintenance phase of 150 mg/m²

Administration

Oral

Give consistently with regard to food.
Do not administer unless absolute neutrophil count >1500 per microliter and platelet count >100,000 per microliter.
Do not open capsules. Avoid inhalation or contact with skin or mucous membranes, if accidentally opened/damaged.
Store at room temperature, 15°–30° C (59°–86° F).

Adverse Effects (≥1%)

Body as a Whole: Headache, fatigue, asthenia, fever, back pain, myalgia, weight gain; viral infection. CNS: Convulsions, hemiparesis, dizziness, abnormal coordination, amnesia, insomnia, paresthesia, somnolence, paresis, ataxia, dysphasia, abnormal gait, confusion, anxiety, depression. CV: Peripheral edema. GI: Nausea, vomiting, constipation, diarrhea, abdominal pain, anorexia. Hematologic: Anemia, neutropenia, thrombocytopenia, leukopenia, lymphopenia. Respiratory: Upper respiratory tract infection, pharyngitis, sinusitis, cough. Skin: Rash, pruritus. Metabolic: Adrenal hypercorticism. Urogenital: Urinary incontinence. Special Senses: Diplopia, abnormal vision.

Interactions

Drug: Valproic acid may decrease temozolomide levels.

Pharmacokinetics

Absorption: Rapidly. Peak: 1 h. Metabolism: Spontaneously metabolized to active metabolite MTIC. Elimination: Primarily in urine. Half-Life: 1.8 h.

Nursing Implications

Assessment & Drug Effects

Monitor for S&S of toxicity: Infection, bleeding episodes, jaundice, rash, CNS disturbances.
Lab tests: CBC with differential on day 22 and weekly until absolute neutrophil count (ANC) >1500 per microliter and platelet count >100,000 per microliter; periodic LFT and routine serum chemistry, including serum calcium.

Patient & Family Education

Take consistently with respect to meals.
Report to physician signs of infection, bleeding, discoloration of skin or skin rash, dizziness, lack of balance, or other bothersome side effects promptly.
Exercise caution with hazardous activities until response to drug is known.
Use effective methods of contraception; avoid pregnancy.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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