Dactinomycin is a cell cycle-nonspecific, antitumor antibiotic that interferes with RNA synthesis.

♦ Wilms’ tumor

♦ Rhabdomyosarcoma

♦ Ewing’s sarcoma

♦ Trophoblastic neoplasms (choriocarcinoma and choriodenoma destruens)

♦ Testicular carcinoma

♦ As an adjunct (given by regional isolation perfusion) to surgery or as palliative treatment of various carcinomas and sarcomas that have not responded to systemic chemotherapy

Slightly metabolized; excreted in urine and bile. Half-life: 36 hours.

♦ Depends on the patient’s tolerance, the clinical response,
and whether other cytotoxic drugs or treatments are being given concomitantly. The drug must be given in short courses. When calculating the dose for obese or ede-matous patients, use the body surface area to relate dosage to lean body mass. Dosage for adults and children should not exceed 15 mcg/kg or 400 to 600 mcg/m² daily IV for 5 days. For adults and children, repeat courses have been given every 2 to 4 weeks, depending on the resolution of drug toxicities.