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Action/Kinetics:
Alkylating agent that inhibits DNA and RNA synthesis through DNA alkylation. It also affects other cellular processes, includling RNA, protein synthesis and the processing of ribosomal and nucleoplasmic messenger RNA; DNA base component structure; the rate of DNA synthesis and DNA polymerase activity. Is cell cycle nonspecific. Rapidly absorbed from the GI tract; crosses the blood-brain barrier resulting in concentrations higher than in plasma.
Peak plasma level: 1-6 hr;
t
1/2: biphasic;
initial, 6 hr;
postdistribution: 1-2 days. From 15% to 20% of drug remains in body after 5 days. Fifty percent of drug excreted within 12 hr through the kidney, 75% within 4 days. Small amounts are excreted through the lungs and feces. Metabolites present in milk.
Uses:
Used alone or in combination to treat primary and metastatic brain tumors. Secondary therapy in Hodgkin's disease (in combination with other antineoplastics).
Contraindications:
Lactation.
Additional Side Effects:
High incidence of N&V; 3-6 hr after administration and lasting for 24 hr. Renal and pulmonary toxicity. Dysarthria.
Delayed bone marrow suppression may occur due to cumulative bone marrow toxicity.
Thrombocytopenia and leukopenia may lead to bleeding and overwhelming infections. Secondary malignancies.
Laboratory Test Alterations:
LFTs (reversible).
How Supplied:
Capsule: 10 mg, 40 mg, 100 mg
Dosage
?Capsules
Adults and children, initial: 130 mg/m
2 as a single dose q 6 weeks. If bone marrow function is reduced, decrease dose to 100 mg/m
2 q 6 weeks. Subsequent dosage based on blood counts of clients (platelet count above 100,000/mm
3 and leukocyte count above 4,000/mm
3). Undertake weekly blood tests and do not repeat therapy before 6 weeks.
