Key Terms: Chemotherapy, Cholesterol, Degenerative diseases, Malignant, Metastatic.
Definition
Estramustine is a combination of two drugs, estradiol and mechlorethamine, that is used to slow the growth of and kill malignant cells in prostate cancer. It is also known by the brand names Emcyt and Estracyte.
Purpose
Estramustine is used in the palliative treatment of metastatic or progressive cancer of the prostate. Palliative treatment helps to relieve symptoms, but does not cure the cancer.
In the early 2000s, estramustine is also being investigated in several clinical trials evaluating its usefulness in managing asymptomatic prostate cancer patients; its effectiveness in combination with docetaxel as an alternative to radical prostatectomy; and its usefulness in increasing the effectiveness of a microtubule drug in treating prostate cancer. These studies suggest that estramustine may have beneficial applications outside the field of palliative care.
Description
Estramustine is classified as an antineoplastic drug. Estramustine is a combination of two drugs: estradiol, a potent female hormone (estrogen), and mechlorethamine, a nitrogen mustard. Its action is to decrease testosterone, increase estrogen level, and suppress cell growth. Estramustine is approved by the United States Food and Drug Administration (FDA) for the palliative treatment of metastatic or progressive cancer of the prostate.
Recommended Dosage
As with many cancer-fighting drugs, the dose of estramustine a patient receives is individualized and depends on the patient's body weight and general health, as well as what other chemotherapy drugs are being used. A standard dose of estramustine is 14 mg per kg of body weight per day, divided into three or four doses. This is equivalent to one 140 mg capsule for each 22 lbs (10 kg) of body weight. It takes one to three months for estramustine to start to work. The therapy is continued as long as the patient has a favorable response. Some patients have successfully taken this drug for as long as three years.
Precautions
Estramustine should not be used by men who have a history of problems with blood clots, a blood clotting disorder, or allergic reactions to estrogen or nitrogen mustard.
Estramustine must be taken more than one hour before or more than two hours after meals. It should not be taken with dairy products, calcium supplements, of any food that is high in calcium.
Patients taking estramustine should avoid having any vaccinations while taking the drug, and should consult their doctor immediately if exposed to chicken pox or measles, as this drug may make them more susceptible to these diseases.
Side Effects
Nausea and vomiting can occur within 2 hours of taking estramustine. This side effect is mild and patients will respond to antiemetics to control the nausea and vomiting. Diarrhea and flatulence can occur while taking this drug. Patients taking estramustine also have an increased risk of developing blood clots, congestive heart failure, and heart attacks, although these side effects are rare. Therefore, men with a history of blood clots and heart disease require frequent monitoring while receiving this drug. Estramustine also decreases the glucose (sugar) tolerance in people with diabetes, and frequent blood sugar monitoring is recommended in this patient population. Blood pressure may also be increased with estramustine, and monitoring of blood pressure is recommended, especially in patients with a history of high blood pressure. Men receiving estramustine may also experience enlargement of their breasts due to the estrogen component in the drug combination. Patients may also experience decreased sexual drive, although this side effect is reversible. If sexually active, the patient should use a contraceptive method (even if he is impotent) prior to initiating therapy, because estramustine may reverse impotency while on the drug. Estramustine may also cause genetic mutations. Therefore, use of contraceptive measures is advisable. Other side effects include lethargy, rash, itching, dry skin, easy bruising, flushing, and thinning hair. If any of the above side effects occur, patients should alert their physician to these side effects immdediately.
Serious side effects that require immediate medical attention include:
- sudden or severe headaches
- sudden shortness of breath or difficulty breathing
- increased weight gain or swelling of the feet or legs
- pain in the chest
- sudden pain or cramping in the legs or calves
- weakness or numbness in the legs or arms
Interactions
Dairy products and other foods containing calcium interfere with the absorption of estramustine. Prior to treatment, patients should notify their physician about any medications they are taking and of any known allergies.
Patients taking estramustine should not use tobacco products, as smoking causes the blood vessels to narrow and may increase the risk of circulation problems during treatment with estramustine..
Estramustine intensifies the effects of vinblastine, another anticancer drug.
Resources
Periodicals
Eastham, J. A., W. K. Kelly, G. D. Grossfeld, et al. "Cancer and Leukemia Group B (CALGB) 90203: A Randomized Phase 3 Study of Radical Prostatectomy Alone Versus Estramustine and Docetaxel Before Radical Prostatectomy for Patients with High-Risk Localized Disease." Urology 62, Supplement 1 (December 29, 2003): 55–62.
Gulley, J., and W. L. Dahut. "Novel Approaches to Treating the Asymptomatic Hormone-Refractory Prostate Cancer Patient." Urology 62, Supplement 1 (December 29, 2003): 147–154.
Oh, W. K. "The Evolving Role of Chemotherapy and Other Systemic Therapies for Managing Localized Prostate Cancer." Journal of Urology 170, 6 Part 2 (December 2003): S28–S32.
Smaletz, O., M. Galsky, H. I. Scher, et al. "Pilot Study of Epothilone B Analog (BMS-247550) and Estramustine Phosphate in Patients with Progressive Metastatic Prostate Cancer Following Castration." Annals of Oncology 14 (October 2003): 1518–1524.
Organizations
United States Food and Drug Administration (FDA). 5600 Fishers Lane, Rockville, MD 20857-0001. (888) INFO-FDA (463-6332).
—Tish Davidson, A.M.; Rebecca J. Frey, PhD
