temozolomide

temozolomide /tem·o·zo·lo·mide/ (tem?ah-zo´lah-mid) a cytotoxic alkylating agent used as an antineoplastic in the treatment of refractory anaplastic astrocytoma.

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temozolomide Warning - Hazardous drug!

Temodal (CA) (UK), Temodar

Pharmacologic class: Alkylating agent

Therapeutic class: Antineoplastic

Pregnancy risk category D

Action

Rapidly converts to monomethyl triazeno imidazole carboxamide, an active compound that prevents DNA transcription

Availability

Capsules: 5 mg, 20 mg, 100 mg, 140 mg, 180 mg, 250 mg

⊘Indications and dosages

➣ Refractory anaplastic astrocytoma

Adults: 150 mg/m² P.O. daily for 5 consecutive days of each 28-day treatment cycle. Adjust dosage as appropriate based on absolute neutrophil count.

Contraindications

• Hypersensitivity to drug, its components, or dacarbazine
• Pregnancy or breastfeeding

Precautions

Use cautiously in:
• severe hepatic or renal impairment, active infection, decreased bone marrow reserve, other chronic debilitating illness
• elderly patients
• patients with childbearing potential
• children (safety not established).

Administration

• Follow facility policy for handling and disposing of chemotherapeutic drugs.
• Give daily with a full glass of water, consistently either with or without food.
• Be aware that dosages in 28-day cycle depend on nadir neutrophil and platelet counts.

Route	Onset	Peak	Duration
P.O.	Rapid	1 hr	Unknown

Adverse reactions

CNS: fatigue, headache, dysphasia, poor coordination, ataxia, anxiety, depression, dizziness, drowsiness, confusion, amnesia, insomnia, mental status changes, weakness, paresis, hemiparesis, paresthesias, seizures

CV: peripheral edema

EENT: abnormal vision, diplopia, pharyngitis, sinusitis

GI: nausea, vomiting, constipation, diarrhea, abdominal pain, anorexia

GU: urinary incontinence or frequency, urinary tract infection, breast pain (in women)

Hematologic: anemia, leukopenia, thrombocytopenia

Metabolic: adrenal hypercorticism

Musculoskeletal: abnormal gait, back pain, myalgia

Respiratory: cough, upper respiratory infection

Skin: pruritus, rash

Other: fever, viral infection, weight gain

Interactions

Drug-drug. Antineoplastics: additive bone marrow depression

Live-virus vaccines: decreased antibody response to vaccine, greater risk of adverse reactions

Valproic acid: decreased oral clearance of temozolomide

Drug-diagnostic tests. Neutrophils, platelets: decreased counts

Patient monitoring

☞ Monitor CBC with white cell differential. Stay alert for evidence of bone marrow depression.
• Assess neurologic status carefully.
• Monitor fluid intake and output, and weigh patient regularly.

Patient teaching

• Tell patient to take consistently with or without food, and with a full glass of water.
• If drug causes nausea or vomiting, advise patient to take it 1 hour before or 2 hours after a meal.
• Inform patient that drug may cause abnormal gait and dizziness.
☞ Instruct patient to immediately report unusual bleeding or bruising.
• Advise patient to avoid live-virus vaccines.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, alertness, and vision.
• Instruct patient to report suspected pregnancy. Caution her not to breastfeed.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.