Estramustine (Emcyt®)

Last Modified: August 21, 2011

Pronounced: ESS-truh-muss-TEEN
Classification: Antineoplastic Agent

About Estramustine

Estramustine is a combination of the chemotherapy nitrogen mustard and a type of estrogen called estradiol. Estramustine works by disrupting the microtubular network in cells that is essential for cell division and other normal cellular functions. The estradiol in estramustine also lowers the body's production of testosterone. Most prostate cancers need supplies of the male hormone testosterone to grow. Without testosterone, the cancer cells may either grow more slowly, or stop growing altogether. Both of these effects work to stop the growth and spread of cancer cells.

How to Take Estramustine

This medication comes as a capsule and your dose is determined based on your body size. It is taken in 3 or 4 doses a day on an empty stomach (1 hour before or 2 hours after a meal). You should not take this medication with milk or other foods or supplements high in calcium or magnesium (including antacids), as this may interfere with its absorption. A typical cycle is 6 weeks of taking estramustine, followed by 2 weeks off of the medication.

Possible Side Effects of Estramustine

There are a number of things you can do to manage the side effects of Estramustine. Talk to your doctor or nurse about these recommendations. They can help you decide what will work best for you. These are some of the most common side effects:

Nausea and/or Vomiting

Take anti-nausea medications as prescribed. If you continue to have nausea or vomiting, notify your doctor or nurse so they can help you manage this side effect. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms. Read the Nausea & Vomiting Tip Sheet for more suggestions.

Call your doctor or nurse if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.


Your oncology team can recommend medications to relieve diarrhea. Also, try eating low-fiber, bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole grain breads, cereals and seeds. Soluble fiber is found in some foods that absorbs fluid and can help relieve diarrhea. Foods high in soluble fiber include: applesauce, bananas (ripe), canned fruit, orange and grapefruit sections, boiled potatoes, white rice and products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses on non-alcoholic, un-caffeinated fluid a day to prevent dehydration. Read Low Fiber Diet for Diarrhea for more tips.


While on cancer treatment you may need to adjust your schedule to manage fatigue. Plan times to rest during the day and conserve energy for more important activities. Exercise can help combat fatigue; a simple daily walk with a friend can help. Talk to your healthcare team and see OncoLink's section on fatigue for helpful tips on dealing with this side effect.

Sexual and Reproductive Changes

This drug can affect your reproductive system, resulting in sperm production becoming irregular or stopping permanently. In addition, you may experience erectile dysfunction or a decreased desire for sex during treatment. Talk to your urologist about options for treating erectile dysfunction.

Exposure of an unborn child to this medication could cause birth defects, so you should not father a child while on this medication. Effective birth control is necessary during treatment, even if you believe your sperm is affected. See OncoLink's section on sexuality for helpful tips for dealing with these side effects.

Breast Tenderness or Increase in Breast Tissue

An increase in breast tissue (gynecomastia) or breast tenderness may develop. Your healthcare team can suggest medications to relieve the tenderness. In rare cases, radiation can be given to relieve severe tenderness.

Fluid Retention / Swelling

Some patients may develop fluid retention, which can cause swelling in the feet and/or ankles or face or gain weight. Fluid can also build up in the lungs and cause you to feel short of breath. Notify your healthcare team if you have any swelling, unexpected weight gain or shortness of breath.

Blood Clots

Blood clots are a rare side effect that can occur anywhere in the body. They are most frequently in the calves or the lungs. People at increased risk for developing blood clots include those with a family history of blood clots, smokers, those who have an inactive lifestyle. Signs of a blood clot in the leg may include any of the following: leg pain, warmth, swelling of one leg more than the other. Signs of a blood clot in the lung could include: fever, shortness of breath that comes on you very quickly, racing heart, chest pain (that tends to be worse when you take a deep breath).

If you have any of these signs of a blood clot, you will need to be seen immediately and be treated. Call your doctor or nurse right away or go to the nearest emergency room.


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