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, just take your next dose at the usual time. Do not take a double dose unless your doctor tells you to.

Other things to remember about your tablets:

• Keep them in their original package and at room temperature, away from heat and direct sunlight.
• Keep them safe and out of sight and reach of children. 
• If you are sick just after taking the tablets, contact your healthcare team. Do not take another dose. 
• 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 tablets exactly as they have been explained to you. Do not stop taking any of your tablets unless your doctor tells you to.

This treatment can make you feel more hungry than usual. This can cause you to gain weight. This effect on your appetite will go away when you stop taking the drug. If you are worried about gaining weight, talk to your doctor or nurse.

Because of this side effect, this treatment is sometimes used to treat people who have lost interest in food and are losing weight.

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 for advice. Your doctor can give you drugs called laxatives to help.

Hot flushes are a common side effect of this treatment. During a flush, your neck and face may feel warm and look red. Flushes may last from a few seconds up to 10 minutes. You may have sweats and then feel cold and clammy. Some people feel anxious or irritable during a hot flush.

There are things you can do to try to reduce flushes:

• Wear clothes made from natural fabrics, such as cotton.
• Wear layers of clothes that you can remove if you feel hot.
• Use cotton bed sheets and have layers of bedding that you can remove if you feel hot.
• Keep room temperatures cool or use a fan.
• Have cold drinks rather than hot ones. Try to avoid drinks with caffeine in them.

You may have fewer hot flushes and sweats as your body adjusts to hormonal treatment. Or your doctor can prescribe drugs to help. Flushes and sweats usually stop a few months after treatment finishes, but some people continue to have them.

We have more information about coping with hot flushes. Women can read more about coping with hot flushes in our information about managing menopausal symptoms.

Cancer and some cancer treatments 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.

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

You may be given anticoagulants to help prevent a clot.

This treatment can raise your blood sugar levels. If you have a raised blood sugar level, you may:

• feel thirsty
• need to pass urine (pee) more often
• feel tired.

Tell your doctor or nurse if you have these symptoms.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this. You may need to change your insulin or tablet dose.

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

• medicines you have been prescribed
• medicines you buy in a shop or chemist
• vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

You are advised not to breastfeed while having this treatment, or for some time after treatment finishes. This is because the drugs could be passed to the baby through breast milk.

Your doctor or nurse can give you more information.

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.

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.