Estramustine phosphate

By Medically reviewed by hellodoktor

Generic Name: Estramustine phosphate Brand Name(s): Generics only. No brands available.


What is estramustine phosphate used for?

Estramustine phosphate works by increasing estrogens, which interfere with prostate cancer, and by slowing/stopping the growth of cancer cells.

Estramustine phosphate is commonly used for treatment some types of prostate cancer.

How should I take estramustine phosphate?

Take this medication by mouth on an empty stomach, either 1 hour before or 2 hours after a meal, usually 3-4 times a day or as directed by your doctor.

Drink with a full glass of water unless your doctor directs you otherwise. Take regularly in order to get the most benefit from it. Remember to take it at the same times each day as directed.

Take this medication 3hours before or after taking any products containing magnesium, aluminum, or calcium, e.g., quinapril, didanosine, vitamins/minerals, and antacids. Dairy products (e.g., milk, yogurt), calcium-enriched juice, sucralfate, bismuth subsalicylate, iron, and zinc are also included.

These products bind with estramustine, preventing its full absorption. Do not increase your dose or take this medication more often than prescribed. Your condition will not improve any faster, and the risk of serious side effects may be increased.

How do I store estramustine phosphate?

Estramustine phosphate is best stored in the refrigerator. To prevent drug damage, do not freeze. There may be different brands of estramustine phosphate that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush estramustine phosphate down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using estramustine phosphate?

Before taking estramustine, tell your doctor or pharmacist if:

  • You are allergic to estramustine phosphate.
  • You are allergic to estradiol, other estrogens, or nitrogen mustard (e.g., mechlorethamine).
  • You have any other allergies.

This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Since this drug can be absorbed through the skin and lungs, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the capsules.

Estrogens combined with smoking further increase your risk for stroke, blood clots, high blood pressure, and heart attacks. If you will be having surgery or will be confined to a chair or bed for a long time (e.g., a long plane flight), notify your doctor beforehand.

Special precautions need to be taken in these circumstances while you are taking this drug because of the increased risk for blood clots.

If you have diabetes, estramustine may worsen control of blood glucose levels. Monitor your blood glucose levels regularly and inform your doctor of the results.

If you are nearsighted or wear contact lenses, you may develop vision problems or trouble wearing your contact lenses. Contact your eye doctor if these problems occur.

This drug may cause a patchy darkening of the skin on the face (melasma). Sunlight may worsen this darkening. Avoid prolonged sun exposure, tanning booths, and sunlamps. Use a sunscreen and wear protective clothing when outdoors.

Is it safe during pregnancy or breastfeeding?

There isn’t enough information about the safety of using this medication during pregnancy and breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking this medication.

Side effects

What side effects can occur from estramustine phosphate?

Nausea, vomiting, loss of appetite, flushing, dry skin, headache, leg cramps, decreased sexual interest/ability, and male breast tenderness/enlargement may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Tell your doctor immediately if any of these unlikely but serious side effects occur:

  • Mental/mood changes (e.g., depression)
  • Swelling of hands/feet
  • Worsening of seizures
  • Signs of worsening diabetes control (e.g., increased thirst and urination)
  • Heart attacks
  • Stroke
  • Blood clots
  • Chest/jaw/left arm pain
  • Sudden severe headache
  • Weakness on one side of the body
  • Confusion
  • Slurred speech
  • Sudden vision changes (e.g., double vision, loss of vision)
  • Pain/redness/swelling of legs
  • Shortness of breath
  • Coughing up blood
  • Sudden dizziness/fainting

Tell your doctor immediately if any of these rare but very serious side effects occur:

  • Easy bruising/bleeding
  • Stomach/abdominal pain
  • Persistent nausea/vomiting
  • Dark urine
  • Yellowing eyes/skin

This medication can lower the body’s ability to fight an infection. Notify your doctor promptly if you develop any signs of an infection such as fever, chills, or persistent sore throat.

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with estramustine phosphate?

Estramustin phosphate may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with estramustine phosphate?

Estramustin phosphate may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with estramustine phosphate?

Estramustin phosphate may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Especially if you have:

  • History of stroke or other blood clots (e.g., in the legs, eyes, lungs)
  • Bone disease (e.g., bone metastases, high calcium levels)
  • High cholesterol or triglyceride (blood fat) levels
  • Depression
  • Diabetes
  • Severe headaches (e.g., migraine)
  • Heart disease (e.g., angina, heart attack, heart failure)
  • High blood pressure
  • Kidney disease
  • Liver disease
  • Seizure
  • Long periods of sitting or lying down (e.g., immobility such as being bedridden)
  • Stroke
  • Thyroid problems


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using estramustine phosphate.

What is the dose of estramustine phosphate for an adult?

Prostate Cancer

The recommended dose is 14 mg/kg/day (range, 10 to 16 mg/kg/day), orally in 3 to 4 divided doses for 30 to 90 days, before assessing for continuation of therapy. Continue therapy as long as response is favorable.

What is the dose of estramustine phosphate for a child?

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is estramustine phosphate available?

Estramustin phosphate is available in the following dosage forms and strengths:

  • Capsules for oral use 140 mg estramustine phosphate

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of estramustin phosphate, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

msBahasa Malaysia

Review Date: April 1, 2017 | Last Modified: September 12, 2019

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