Megestrol acetate (Megace®)

Hormones are chemicals that our bodies make. Hormones act as messengers and help control how cells and organs work. Hormonal therapies are drugs that change the way hormones are made or how they work in the body.

Many cancers need hormones to grow. Megestrol is similar to the female sex hormone progesterone. It works by changing the hormone balance in the body, which may stop the cancer growing. It can also act directly on cancer cells so that they cannot grow.

Megestrol comes as tablets you can take at home. Your nurse or doctor will talk to you about your treatment plan.

Always take the tablets exactly as explained. This is important to make sure they work as well as possible for you. Make sure you:

• swallow them whole with a glass of water
• take them at the same time every day. 

If you forget to take the tablets, you should take the missed dose as soon as possible within the same day. If it is nearly time for your next dose, skip the forgotten one and take the next one as usual. Do not take a double dose.

Other things to remember about your tablets:

• Keep them in the original package and at room temperature, away from heat and direct sunlight.
• Keep them safe and out of sight and reach of children.
• Get a new prescription before you run out of tablets, and make sure you have plenty for holidays.
• If your treatment is stopped, return any unused tablets to the pharmacist. 

Take all your medicines exactly as they have been explained to you. Do not stop taking any of your medicines unless your doctor tells you to.

Megestrol can make you hungrier than usual. This may mean you gain weight. Your appetite should return to normal when you stop taking megestrol.

If you are worried about gaining weight, your doctor, nurse or dietitian can give you more advice.

Because of this side effect, megestrol is sometimes used to treat people who have lost their appetite.

Hot flushes are a common side effect of this treatment. During a flush, your neck and face may feel warm. If you have white skin, your skin may look red. If you have black or brown skin, your skin colour may deepen. Flushes may last up to 5 minutes. You might also have sweats or feel anxious or irritable during a hot flush.

Here are some things you can do to reduce the effects of hot flushes:

• Wear natural fabrics, such as cotton.
• Wear layers so you can remove clothes as needed.
• Use cotton sheets and layers of bedding you can remove.
• Try cooling pads or pillows to keep you cool.
• Keep rooms cool or use a fan.
• Have cold drinks and avoid caffeine and alcohol. 

You might have fewer hot flushes as your body adjusts to this treatment. You could try therapies to help you cope with hot flushes, such as:

• talking therapies like cognitive behaviour therapy (CBT)
• controlled breathing exercises
• yoga 
• acupuncture. 

If they do not improve, talk to your doctor. Certain drugs can help to improve hot flushes. 

Flushes usually stop a few months after treatment ends. But some people continue to have them.

This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. Here are some tips that may help:

• Drink at least 2 litres (3½ pints) of fluids each day.
• Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
• Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital on the 24-hour number for advice. They can give you drugs called laxatives to help. 

If you have not been able to pass stools for over 2 days and are being sick, contact the 24-hour number straight away. 

This treatment can raise your blood sugar levels and increase the risk of diabetes. 

Signs of raised blood sugar include:

• feeling thirsty
• needing to pass urine (pee) more often than usual
• feeling more tired than usual. 

Tell your doctor or nurse if you have these symptoms. They can do tests to check your blood sugar level and give you advice.

If you already have diabetes, your blood sugars may be higher than usual. You may need to check them more often, or make changes to your diabetic treatment. Your diabetic doctor or nurse will talk to you about how to manage this.

Cancer and some cancer drugs such as megestrol can increase the risk of a blood clot. Symptoms of a blood clot include:

• throbbing pain, redness or swelling in a leg or arm
• suddenly feeling breathless or coughing
• sharp chest pain, which may be worse when you cough or take a deep breath. 

If you have any of these symptoms, contact the hospital straight away on the 24-hour contact number you have been given. If you cannot get through to your doctor, call the NHS urgent advice number on 111.

A blood clot is serious, but it can be treated with drugs that thin the blood (anticoagulants). Your doctor or nurse can give you more information. 

You can help reduce the risk of developing a blood clot by:

• staying active during treatment 
• drinking plenty of fluids, especially water. 

You may be given anticoagulants to help prevent a clot.

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

• medicines you have been prescribed
• medicines you buy in a shop, pharmacy or online
• vitamins or supplements 
• herbal drugs and complementary or homeopathic therapies
• recreational drugs – for example, cannabis.

These tablets contain a type of sugar called lactose. If you have been told by a doctor that you cannot digest some sugars or are lactose intolerant, talk to your doctor before taking this drug.

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Your doctor, nurse or pharmacist will advise you not to get pregnant while having this treatment. The drug may harm a developing baby. It is important to use contraception to prevent pregnancy. Follow their advice about:

• what types of contraception to use, for example using barrier contraception instead of hormonal contraception like the oral pill
• how long after treatment you should continue to use contraception.

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.