Posted on December 2nd, 2008 by

Class: Hormonal agent

Generic Name: Megestrol acetate (MEJ-eh-strol ASS-eh-tate)
Trade Name: Megace®

How is this drug used? Megestrol acetate is FDA approved for the treatment of inoperable, recurrent or metastatic uterine or breast cancer. It is important for patients to remember that physicians have the ability to prescribe medication for conditions other than those for which the drug has been approved by the FDA. Patients who have received a prescription of this drug for a condition other than which it is approved may wish to discuss this issue with their physician.

What is the mechanism of action? Megestrol acetate is classified as a hormonal agent. Megestrol acetate is a type of synthetic (laboratory made) progesterone, which is a female hormone. Progesterone tends to reduce levels of a different hormone, estrogen, in the body. Certain cancers are stimulated to grow from exposure to estrogen, and it is believed that megestrol acetate may reduce the levels of estrogen produced in a body, which inhibits the growth of cancers that are stimulated to grow by estrogen.

How is megestrol acetate given (administered)? Megestrol acetate is given orally, either in the form of a tablet or liquid and the dose depends on several factors, including the condition being treated, the size of the patient, the particular regimen being used and the overall health of the patient.

How are patients monitored? Patients will usually have scheduled meetings with their healthcare provider while they are being treated with megestrol acetate.  Patients may undergo physical examinations, scans or other measures to assess side effects and response to therapy.

Patients may also be monitored for fluid retention that results in swelling. Patients will have electrolyte and blood sugar levels monitored through blood tests. In addition, patients may have their heart function monitored, including blood pressure readings. Patients will be monitored for blood clots, which may result in swelling, pain or redness of one extremity and not the other, sudden difficulty in breathing, severe headache or vision changes.

What are the most common side effects of treatment with megestrol acetate?

• Weight gain (associated with increased appetite)
• Fluid retention, resulting in swelling of the feet or hands
• Breakthrough menstrual bleeding, spotting
• Hot flashes
• Decreased libido
• Weakness
• Rash
• Sweating

This is not a complete list of side effects. Some patients may experience other side effects that are not listed here. Patients may wish to discuss with their physician the other less common side effects of this drug, some of which may be serious.

Some side effects may require medical attention. Other side effects do not require medical attention and may go away during treatment. Patients should check with their physician about any side effects that continue or are bothersome.

What can patients do to help alleviate or prevent discomfort and side effects?

• Pay careful attention to the physician’s instructions and inform the physician of any side effects.
• Maintain adequate rest and nutrition.
• Wear sunscreen and protective clothing and try to minimize sun exposure.
• Drink plenty of fluids. (Patients should ask their physician about the amount of liquid to consume during a day.)
• Patients who experience hot flashes may wish to wear light clothing, stay in a cool environment, and place cool cloths on their body or head to relieve their symptoms.

Are there any special precautions patients should be aware of before starting treatment?

• Patients should inform their physician if they are pregnant, breastfeeding or planning a family in the near future. This drug may cause birth defects. It is important to use some kind of birth control while undergoing treatment. Also, patients may want to talk to their physician if they are considering having children in the future, since some drugs may cause fertility problems.
• It is important that patients inform their physician of any pre-existing conditions (chicken pox, heart disease, kidney disease, liver disease, lung disease, etc.) as they may worsen with this drug.
• Patients should inform their physician of any other medication they are taking (whether prescription or over-the-counter, including vitamins, herbs, etc.) as they may interfere with treatment.
• Patients should check with their physician before starting any new drug or nutritional supplement.
• Patients should inform their physician of any known drug or food allergies or any reactions to medications they have experienced in the past.
• If an oral dose is missed, do not double up on doses.  Patients should contact their physician in this event.
• Keep tablets out of reach of children and return to the pharmacy for safe disposal if treatment is terminated.

When should patients notify their physician?

• Nausea
• Vomiting
• Dizziness
• Weakness or numbness
• High blood pressure
• Chest pain or palpitations
• Swelling, pain or redness of one extremity and not the other
• Sudden difficulty in breathing, severe headache or vision changes
• Sudden slurring of speech or difficulty speaking
• Mood changes, depression
• Change in menstrual bleeding or periods

What is a package insert?
A package insert is required by the FDA and contains a summary of the essential scientific information needed for the safe and effective use of the drug for healthcare providers and consumers.  A package insert typically includes information regarding specific indications, administration schedules, dosing, side effects, contraindications, results from some clinical trials, chemical structure, pharmacokinetics and metabolism of the specific drug. By carefully reviewing the package insert, you will get the most complete and current information about how to safely use this drug. If you do not have the package insert for the drug you are using, your pharmacist or physician may be able to provide you with a copy.

Copyright © 2016 CancerConnect Last updated 07/10.

Important Limitations of Use

The information provided above on the drug you have selected is provided for your information only and is not a substitute for consultation with an appropriate medical doctor. We are providing this information solely as a courtesy and, as such, it is in no way a recommendation as to the safety, efficacy or appropriateness of any particular drug, regimen, dosing schedule for any particular cancer, condition or patient nor is it in any way to be considered medical advice. Patients should discuss the appropriateness of a particular drug or chemotherapy regimen with their physician.

As with any printed reference, the use of particular drugs, regimens and drug dosages may become out-of-date over time, since new information may have been published and become generally accepted after the latest update to this printed information. Please keep in mind that health care professionals are fully responsible for practicing within current standards, avoiding use of outdated regimens, employing good clinical judgment in selecting drugs and/or regimens, in calculating doses for individual patients, and verifying all dosage calculations.



The prescribing physician is solely responsible for making all decisions relating to appropriate patient care including, but not limited to, drugs, regimens, dose, schedule, and any supportive care.

Tags: Hormonal Therapy, M

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