Dactinomycin
Definition
Dactinomycin is a chemotherapeutic agent belonging to a family of medicines known as antineoplastic drugs. Alternative trade names or brand names for dactinomycin include Actinomycin-D and Cosmegen.
Description
Dactinomycin is one of the older chemotherapy drugs, having gained approval from the Food and Drug Administration (FDA) in 1982. This highly potent and effective cytotoxic agent is a mixture of substances produced by the bacteria Streptomyces parvullus. Its toxic properties prevent its use as an antibiotic.
Dactinomycin interferes with the growth of cancer cells by complexing with a cell's genetic material (deoxyribonucleic acid, or DNA). This prevents the cell from producing the proteins necessary to function and grow, thereby killing it. Dactinomycin may be used as a single chemotherapeutic agent or in conjunction with other antineoplastics (such as vincristine and cyclophosphamide) for greater efficacy.
Purpose
Dactinomycin is used in the treatment of Ewing's sarcoma, Wilms' tumor, rhabdomyosarcoma, gestational trophoblastic tumors, Kaposi's sarcoma, and soft tissue sarcomas. It is less commonly used for cancers of the uterus and testis.
Recommended dosage
The exact schedule and method of dactinomycin administration will be prescribed by an oncologist based on the type and stage of the cancer. An appropriate starting treatment regimen for adult patients is 500 mg/day for five consecutive days at two to four week intervals if the drug is tolerated. For children the dose is 15 mg/day over the same time course as prescribed for adults. Dactinomycin is not recommended for children less than one year of age; little clinical data is available on the use of dactinomycin in the elderly. Administration may be by intravenous (IV) injection, through a running IV infusion, or through a central line inserted under the skin into a vein near the collarbone.
Precautions
To maximize treatment effects, patients receiving dactinomycin should observe the following guidelines, as well as any modifications given by the oncologist:
- The area surrounding the injection site should be monitored.
- Patients should have regular laboratory testing for white blood cell count and kidney, liver, and bone marrow function.
- In order to reduce the possibility of immunosuppression, immunizations not approved or prescribed by the oncologist should be avoided.
- Patients should avoid contact with individuals taking or that have recently taken the oral polio vaccine, or individuals that have an active infection. When necessary a protective facemask should be worn.
- Oral hygiene procedures should be followed to reduce the risk of gum abrasion.
- Patients should not touch eye and nasal areas unless hands have been properly washed immediately prior to contact.
- To reduce bleeding and bruising complications, patients should exercise extreme caution when handling sharp instruments and decline participation in contact sports.
- Prior to treatment, the patient's medical history should be thoroughly reviewed to avoid complications that might arise from previous conditions such as gout, kidney stones, liver disease, chickenpox, shingles, or a history of allergic reactions to various drugs.
- The oncologist should be made aware if the patient is pregnant or if there is the possibility the patient might be pregnant, or if the patient is a breast-feeding mother.
- Only prescribed medications or over the counter (OTC) drugs approved by the oncologist should be taken by a patient receiving dactinomycin.
