lomustine

Action

Inactivates neoplastic cells by alkylating DNA, causing DNA structural modification and fragmentation. Thought to act in late G1 or early S phase of cell cycle.

Availability

Capsules: 10 mg, 40 mg, 100 mg

Dose pack: two 10-mg capsules, two 40-mg capsules, and 100-mg capsules

Indications and dosages

➣ Adjunctive therapy in primary and metastatic brain tumors; secondary therapy in Hodgkin's disease

Adults and children: As monotherapy, 130 mg/m² P.O. as a single dose q 6 weeks in previously untreated patients. In bone marrow suppression, initial dosage is 100 mg/m² P.O. q 6 weeks; don't repeat dose until platelet count exceeds 100,000/mm³ and white blood cell (WBC) count exceeds 4,000/mm³. When given with other myelosuppressive drugs, adjust dosage accordingly.

Dosage adjustment

• Bone marrow depression (based on WBC and platelet counts)

Contraindications

• Hypersensitivity to drug

Precautions

Use cautiously in:

• renal or hepatic dysfunction, bone marrow depression

• pregnant or breastfeeding patients.

Administration

• Obtain CBC with white cell differential before starting therapy.

• Administer antiemetic before giving drug, as prescribed, to minimize nausea.

• Give 2 to 4 hours after meals to enhance absorption.

• If vomiting occurs shortly after administration, notify prescriber.

Adverse reactions

CNS: anxiety, confusion, dizziness, hallucinations, lethargy, headache, paresthesia, light-headedness, drowsiness, fatigue, seizures

GI: nausea; vomiting; anorexia; sore mouth, lips, and throat; GI bleeding

GU: amenorrhea, azoospermia, progressive azotemia, nephrotoxicity, renal failure

Hematologic: anemia, leukopenia, thrombocytopenia, bone marrow depression

Hepatic: hepatotoxicity

Skin: alopecia

Other: secondary cancers

Interactions

Drug-drug. Anticoagulants, non-steroidal anti-inflammatory drugs: increased bleeding risk

Myelosuppressants: increased bone marrow depression

Drug-diagnostic tests. Hemoglobin, platelets, red blood cells, WBCs: decreased values

Liver function tests, nitrogenous compounds: increased values

Patient monitoring

☞ Watch for evidence of overdose, including bone marrow depression, nausea, and vomiting.

☞ Monitor CBC and platelet counts closely. Watch for signs and symptoms of bleeding and bruising.

• Avoid I.M. injections if platelet count is below 100,000/mm³.

• Check kidney, liver, and pulmonary function tests frequently.

• Assess neurologic status carefully. Institute safety measures as needed to prevent injury.

☞ Watch for signs and symptoms of secondary cancers.

Patient teaching

• Instruct patient to contact prescriber if he vomits shortly after taking drug.

☞ Tell patient to immediately report easy bruising or bleeding, which may signal low platelet count.

• Advise patient to report changes in urination pattern.

• Instruct patient to avoid exposure to people with infections, because drug may make him more susceptible to infection.

☞ Caution female of childbearing age to use reliable contraception and to immediately report suspected or confirmed pregnancy.

• Advise female patient to inform prescriber if she is breastfeeding.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Advise patient to minimize GI side effects by eating small, frequent servings of healthy food.

• Inform patient that drug may cause hair loss.

• Tell patient he'll undergo frequent blood testing during therapy.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.