Estramustine (Emcyt®)

OncoLink Team
Last Modified: September 28, 2015

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) – this may take some planning! You should not take this medication with milk or other foods or supplements high in calcium or magnesium (including antacids), as they may interfere with its absorption. Take the capsules whole, do not open, break or chew.

A typical cycle is 6 weeks of taking estramustine, followed by 2 weeks off of the medication.

Storage and Handling

Store your medication in the original, labeled container in the refrigerator (unless otherwise directed by your healthcare provider or pharmacist). This medication should not be stored in a pillbox. Keep containers out of reach of children and pets.


If a caregiver prepares your dose for you, they should consider wearing gloves or pour the pills directly from their container into the cap, a small cup, or directly into your hand. They should avoid touching the pills. They should always wash their hands before and after giving you the medication. Pregnant or nursing women should not prepare the dose for you. Ask your oncology team where to return any unused medication for disposal. Do not flush down the toilet or throw in the trash.


Where do I get this medication?

Estramustine is available through select specialty pharmacies. Your oncology team will work with your prescription drug plan to identify an in-network specialty pharmacy for distribution of this medication and shipment directly to your home. 

Insurance Information

This medication may be covered under your prescription drug plan. Patient assistance may be available to qualifying individuals without prescription drug coverage. Co-pay cards, which reduce the patient co-pay responsibility for eligible commercially (non-government sponsored) insured patients, are also available. Your care team can help you find these resources, if they are available.

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:

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.

Nausea and/or Vomiting

Talk to your doctor or nurse so they can prescribe medications to help you manage nausea and vomiting. 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.

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.

Fluid Retention / Swelling

Some patients may develop fluid retention, which can cause swelling in the feet, ankles, or face, or cause weight gain. 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 and Heart Attack

Estramustine can increase the risk of blood clots and heart attack. If you experience symptoms of these problems, you should contact your healthcare provider immediately or go to an emergency room. Symptoms can include: swelling, redness or pain in an extremity, chest pain or pressure, pain in your arm, back, neck or jaw, or shortness of breath.

Other Side Effects

This medication can cause elevated blood glucose in patients with diabetes. Diabetics should monitor their blood sugar and notify your provider of elevations.

This medication can cause high blood pressure. Your blood pressure should be monitored periodically while taking estramustine.

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 you are not producing sperm. You may want to consider sperm banking if you may wish to have a child in the future. Discuss these options with your oncology team.



If you have questions or concerns about the medication that you have been prescribed, please contact your healthcare team. OncoLink is designed for educational purposes only and is not engaged in rendering medical advice or professional services. The information provided through OncoLink should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care. If you have or suspect you may have a health problem, you should consult your health care provider.


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