Megestrol Acetate

What is Megestrol Acetate?

Megestrol acetate is a prescription medicine. It belongs to a drug class called progestins, which are man-made versions of the hormone progesterone. It was first sold under the brand name Megace, and generic versions are available.

Megestrol acetate comes in different forms, and each form has its own approved use:

• Tablets: Approved in the United States for the palliative treatment of advanced breast cancer or endometrial (uterine lining) cancer. “Palliative” means the goal is to ease symptoms and help control the disease.
• Oral suspension (liquid): Approved for the treatment of anorexia, cachexia, or unexplained significant weight loss in people with AIDS.

Formulations and strengths: Tablets are available in 20 mg and 40 mg strengths. The oral suspension is available in 40 mg/mL and as a more concentrated 125 mg/mL product. Other uses should be discussed only with your doctor.

What is the Recommended Dosage of Megestrol Acetate?

Your dose is set by your doctor and should always follow their instructions and your pharmacy label. The dose depends on the form you are prescribed and the condition being treated. Tablets are taken by mouth in divided doses during the day. The liquid is measured with a dosing syringe or cup and taken by mouth.

Important points:

• Not interchangeable: The 40 mg/mL and 125 mg/mL liquids have different dosing. Always check the label and measure the exact amount your doctor prescribed.
• Shake the liquid well before each dose.

Your care team may adjust the dose or schedule based on:

• Your condition and response: Treatment may be changed if side effects occur or if it is not helping.
• Kidney function: Megestrol acetate is cleared in part by the kidneys, so kidney problems may require closer monitoring.
• Other medicines: Some drugs can affect how megestrol acetate works.
• Overall health: Age and other conditions can matter.

Do not change, skip, or suddenly stop doses on your own. Stopping suddenly after long-term use can lead to problems with the adrenal glands, so follow your care team’s directions.

How Megestrol Acetate Works

Megestrol acetate acts like the natural hormone progesterone. Its exact way of working is not fully understood.

In breast and endometrial cancers that respond to hormones, it is thought to slow cancer cell growth by changing how hormones signal the cells. In people with AIDS-related weight loss, it increases appetite and can lead to weight gain. Megestrol acetate is used to help manage these conditions and is not considered a cure. Regular visits help your care team see how treatment is working.

Is a Prescription Required to Buy Megestrol Acetate Online?

Yes. Megestrol acetate is prescription-only. It should be prescribed and monitored by a licensed medical specialist, such as a medical oncologist or gynecologic oncologist (for breast or endometrial cancer), or an infectious disease or HIV specialist (for AIDS-related weight loss).

• Buy only from a licensed pharmacy that requires a valid prescription.
• Counterfeit or substandard medicines exist. Be cautious of websites that sell without a prescription or ship from unclear sources.
• Check that the tablets or liquid match what your pharmacist describes, and ask your pharmacist if packaging or appearance looks different.

Side Effects of Megestrol Acetate

Not everyone gets every side effect. Many can be managed with help from your care team.

Common Side Effects

• Weight gain and increased appetite
• Nausea, vomiting, or diarrhea
• Hot flashes
• Swelling in the hands, feet, or ankles
• Headache
• Mood changes
• Vaginal bleeding or spotting between periods
• Rash
• Trouble with erections or decreased interest in sex (in men)
• Higher blood sugar

Serious Side Effects

These are less common but need prompt attention:

• Blood clots: leg pain or swelling, sudden chest pain, sudden shortness of breath, or signs of stroke
• Adrenal problems: extreme weakness, dizziness, nausea, low blood pressure, or fainting, especially during illness, injury, or after stopping the medicine
• High blood sugar or diabetes: increased thirst, frequent urination, or blurred vision
• Heart problems and fluid retention: shortness of breath, rapid weight gain, or heart failure symptoms
• High blood pressure
• Severe allergic reaction: swelling of the face, lips, or throat, trouble breathing, or widespread rash
• Numbness or tingling in the hands (carpal tunnel syndrome has been reported)

Seek immediate medical care if you have chest pain, sudden trouble breathing, signs of a blood clot or stroke, swelling of the face or throat, or fainting. Contact your care team promptly for unusual bleeding, severe weakness, or any symptom that worries you.

Drug Interactions

Tell your doctor and pharmacist about everything you take, including prescription drugs, over-the-counter (OTC) products, vitamins, supplements, and herbal products. Major categories include:

• Warfarin and other blood thinners: Megestrol acetate may change their effect, so closer monitoring may be needed.
• Corticosteroids (such as prednisone or dexamethasone): Using them with megestrol acetate may add to effects on blood sugar and the adrenal glands.
• Diabetes medicines and insulin: Megestrol acetate can raise blood sugar, so doses may need adjusting.
• HIV medicines: Megestrol acetate may lower the levels of certain HIV medicines, such as indinavir. Your care team will review your HIV treatment plan.
• Other hormone products: Estrogen or other progestin products may add to or change effects.
• Herbal products and supplements: Some can affect hormones or blood clotting. Ask your pharmacist before using any herbal or dietary supplement.

Bring a complete, updated medication list to every appointment.

Safety & Important Considerations

• Blood clots: Tell your team about any history of blood clots, stroke, or heart disease. The risk may be higher in people who are older, less active, or have cancer.
• Adrenal suppression: Long-term use can lower the body’s natural steroid hormones. Your team may advise extra care during serious illness, surgery, or injury.
• Blood sugar: Blood sugar may be monitored, especially in people with diabetes.
• Blood pressure and fluid retention: Report swelling, rapid weight gain, or shortness of breath.
• Liver disease: Discuss any liver problems with your specialist.
• Kidney disease: Discuss any kidney problems with your specialist.
• Pregnancy: Megestrol acetate can harm an unborn baby and is not for use during pregnancy. Women who could become pregnant should use effective contraception during treatment, as directed by their doctor. Tell your doctor right away if you are or may become pregnant.
• Breastfeeding: Breastfeeding is not recommended during treatment.
• Older adults and children: Older adults are monitored closely for blood clots and kidney function. Safety and effectiveness in children have not been established.
• Weight and nutrition: For people using the liquid for weight loss, the care team will track weight, nutrition, and overall health.
• Monitoring: Expect regular visits, and possibly blood tests for blood sugar and other health checks.

Who This Medication Is For

Megestrol acetate tablets are intended for adults with advanced breast cancer or endometrial cancer, as decided by their cancer care team. The oral suspension is intended for people with AIDS who have anorexia, cachexia, or unexplained significant weight loss, as decided by their care team. Treatment plans differ from person to person.

Who Should Not Take Megestrol Acetate

Megestrol acetate should not be used by people who:

• Have had a severe allergic reaction to megestrol acetate or any ingredient in the tablet or liquid
• Are pregnant, because it can harm an unborn baby

Discuss with your doctor before starting if you:

• Have a history of blood clots, stroke, or heart disease
• Have diabetes or high blood sugar
• Have high blood pressure or heart failure
• Have liver disease or kidney disease
• Have adrenal gland problems or take long-term steroid medicine
• Are planning pregnancy or breastfeeding
• Take medicines that interact with megestrol acetate

What to Do If You Miss a Dose

• Take the missed dose as soon as you remember, unless it is almost time for your next dose. In that case, skip the missed dose and continue with your regular schedule.
• Never take two doses at once to make up for a missed one.
• If you are unsure what to do, or you miss several doses, contact your care team or pharmacist.

Related medications to Megestrol Acetate

Other medicines are used for the same conditions, depending on the condition and your health:

• Advanced breast cancer: aromatase inhibitors (anastrozole, letrozole, exemestane), tamoxifen, fulvestrant, and targeted therapies such as CDK4/6 inhibitors
• Endometrial cancer: other hormone therapies such as medroxyprogesterone acetate or tamoxifen, chemotherapy, targeted therapy, immunotherapy, radiation, or surgery
• AIDS-related weight loss: nutrition counseling, oral nutritional supplements, other appetite-related medicines such as dronabinol, and treatment of the underlying causes of weight loss

These medicines differ in side effects, interactions, and approved uses. Switching or combining treatments must be decided together with your doctor.

Storage Instructions

• Tablets: Store at room temperature, about 68°F to 77°F (20°C to 25°C), in the original container with the lid tightly closed. Protect from heat and moisture.
• Oral suspension: Store at room temperature, about 68°F to 77°F (20°C to 25°C), with the cap tightly closed. Do not freeze. Protect from heat. Shake well before use.
• Keep away from moisture (not in the bathroom) and light.
• Keep out of reach of children and pets.
• Do not use past the expiration date. Ask your pharmacist about safe disposal of unused medicine.
• Caregivers handling the medicine should wash their hands afterward, and pregnant caregivers should ask the care team about handling precautions.

Disclaimer:

This page is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Patients must consult a licensed medical oncologist, gynecologic oncologist, or other relevant medical specialist before starting, changing, or stopping treatment. Treatment decisions must be based on a full clinical evaluation by a qualified specialist.