Bleomycin
Bleomycin
Definition
Bleomycin (Blenoxane) kills cancer cells by damaging the genetic material known as DNA, thus preventing cells from repairing themselves.
Purpose
Bleomycin is used in the treatment of a number of different cancers, including cancer of the head and neck, skin, esophagus, lung, testis, penis, vulva, cervix, and genitourinary tract. In addition, it is used in the treatment of Hodgkin's disease and non-Hodgkin's lymphomas . It may also be used to treat Kaposi's sarcoma .
Because bleomycin is used in the treatment of so many different cancers, only a sampling of its uses can be provided here. In the treatment of Hodgkin's disease, one chemotherapy regimen used is the so-called ABVD, which consists of doxorubicin , bleomycin, vinblastine , and dacarbazine . Another regimen is called MOPP/ABV, which consists of mechlorethamine , vincristine , prednisone, procarbazine , doxorubicin, bleomycin, and vinblastine.
A treatment used for stage III and IV non-Hodgkin's lymphoma is the CHOP-bleomycin regimen, which consists of cyclophosphamide , hydroxydaunomycin, vincristine, prednisone, and bleomycin. Another approach to the same illness involves the m-BACOD chemotherapy regimen, which consists of methotrexate , bleomycin, doxorubicin, cyclophosphamide, vincristine, and dexamethasone . Yet another approach to treating this disease is called ProMACE-CytaBOM, and consists of cyclophosphamide, doxorubicin, etoposide , prednisone, cytarabine , bleomycin, vincristine, methotrexate, and leucovorin .
Description
Bleomycin is an antitumor antibiotic that fights cancer by attacking the DNA in cancerous cells, thus interfering with cell growth.
Recommended dosage
A dose of 0.25-0.50 units/kg (10-20 units per square meter) is given once or twice a week either intravenously, intramuscularly, or subcutaneously. A small test dose should be given first to test for a possible severe allergic reaction.
Precautions
Patients who receive certain forms of oxygen therapy while taking bleomycin or who receive anesthesia while taking bleomycin are at increased risk for developing serious lung problems.
Patients given bleomycin may develop an acute allergic reaction that may be fatal in rare cases. Therefore, a patient should only receive a small test dose of bleomycin the first time the drug is administered. After this initial dose the patient is observed carefully for one hour. Assuming no further problems appear, the patient may then receive a standard dose.
The likelihood that lung damage will occur increases if a patient receives more than 450-500 units of the drug during an entire lifetime. So, it is prudent to limit the amount of this medication given. Furthermore, it may be unwise to give bleomycin in regimens containing cyclophosphamide, as this combination also increases the likelihood that lung damage will occur.
Side effects
Lung problems are a serious side effect affecting some patients who receive bleomycin. While lung problems can appear regardless of how much of the medicine is given, they are more likely to appear if a patient receives more than a certain amount of the medicine— 250 units according to some authorities and 450-500 units according to others. The appearance of a dry cough may indicate the development of lung problems. Lung damage can be assessed by measuring the rate at which the patient is able to transfer gas across the lung membranes (DLCO or diffusion lung capacity).
Other side effects of bleomycin may include skin problems and alteration of skin color, allergic reactions, Raynaud's phenomenon, and hair loss. In addition, headache, and nausea and vomiting may occur. Rheumatoid arthritis may worsen during bleomycin therapy. Patients with testicular tumors who receive multiple chemotherapy agents including bleomycin may develop Raynaud's phenomenon and cardiovascular disease. Raynaud's phenomenon, which affects the fingers and toes, may involve pain, pale color, and abnormal sensation (for instance, burning or prickling).
Approximately 1 out of every 100 patients who takes bleomycin experiences a reaction that involves chills, fever , wheezing, low blood pressure, and mental confusion. Unlike many other cancer drugs, bleomycin is not likely to cause any damage to the bone marrow.
Patients may be given steroids before bleomycin therapy is started in an effort to reduce the side effects of the drug.
Interactions
Bleomycin is often given in combination with with other anticancer drugs, for example cisplatin , vinblastine, and etoposide. Such combinations have been found to be more effective than single drug therapy.
Bob Kirsch
KEY TERMS
DNA
—DNA is a nucleic acid found inside of cells that carries genetic information.
Raynaud's phenomenon
—Raynaud's phenomenon, which affects the fingers and toes, may involve pain, pale color, and abnormal sensation (e.g., burning or prickling).