Relugolix (Orgovyx)
Relugolix is a type of hormone therapy. You pronounce it as reh-loo-goh-lix. It is also known as Orgovyx.
It is a treatment for advanced prostate cancer, that is hormone dependent. Hormone dependent means that the cancer cells need a hormone to grow.
How does relugolix work?
Prostate cancer usually depends on the hormone testosterone to grow. Hormone therapy blocks or lowers the amount of testosterone in the body. This aims to slow the growth of cancer or shrink it.
Relugolix works by blocking messages from a part of the brain called the hypothalamus that tell the 
to produce luteinising hormone and follicle stimulating hormone. Luteinising hormone and follicle stimulating hormone tells the testicles to produce testosterone. So relugolix stops the testicles making testosterone.
This type of hormone therapy is called a gonadotrophin-releasing hormone antagonist or GnRH blocker.
How do you take relugolix?
You take relugolix as tablets.
You swallow them whole with a glass of water. You can have the tablets with or without food.
You should take the right dose, not more or less.
Talk to your healthcare team before you stop taking a cancer drug, or if you miss a dose.
How often do you take relugolix?
On the first day you take 3 tablets. From day 2 onwards, you take 1 tablet once a day.
Try to take the tablet at the same time each day.
You continue taking relugolix for as long as the treatment is working and you are not experiencing too many side effects.
Tests
You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.
You might have tests to check your heart, such as an .
What are the side effects of relugolix?
Side effects can vary from person to person. They also depend on what other treatment you are having.
When to contact your team
Your doctor, nurse, or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:
-
you have severe side effects
-
your side effects aren’t getting any better
-
your side effects are getting worse
Early treatment can help manage side effects better.
We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.
Remember it is very unlikely that you will have all of these side effects, but you might have some of them at the same time.
Common side effects
These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:
Hot flushes
We have some tips for coping with hot flushes in men. This information also includes some of the possible treatments. Talk to your doctor if your hot flushes are hard to cope with. They might be able to prescribe you some medicines.
Diarrhoea
Contact your advice line if you have diarrhoea. For example, in one day you have 2 or more loose bowel movements than usual. If you have a , you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.
Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain fibre. But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables.
Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.
Constipation
is easier to sort out if you treat it early. Drink plenty and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking. Tell your healthcare team if you think you are constipated. They can give you a laxative if needed.
Muscle and joint pain
You might feel some pain from your muscles and joints. Speak to your doctor or nurse about what painkillers you can take to help with this.
Tiredness (fatigue)
You might feel very tired and as though you lack energy.
Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.
Occasional side effects
These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:
- a drop in
red blood cells that can cause breathlessness, tiredness and looking pale - growth of breast tissue (gynaecomastia) - talk to your doctor if this becomes a problem
- difficulty sleeping or getting to sleep
- feeling very low and sad (depression)
- dizziness
- headache
- high blood pressure
- feeling sick (nausea)
- sweating more than usual
- a rash, including raised itchy bumps (hives)
- a decrease in your sex drive
- weight gain
- high blood sugar levels
- high levels of fatty substances called cholesterol and triglyceride in the blood
Rare side effects
These side effects happen in fewer than 1 in 100 people (less than 1%). You might have one or more of them. They include:
- weakened bones that are fragile and more likely to break (osteoporosis)
- changes to the way your liver works
- an allergic reaction needing treatment – signs include fainting, sweating, tiredness, swelling of the face, lips, mouth, tongue or throat
Other side effects
You might have changes to the electrical activity of your heart. There isn't enough information to work out how often this side effect might happen. Tell your healthcare team straightaway if you feel dizzy, faint, like your heart is racing (palpitations) or have chest pain. Very rarely this can cause a heart attack.
Possible rare and long term side effects
This is a new drug in cancer treatment. So there is limited information available at the moment about possible rare and longer term effects that it may cause. Tell your doctor if you notice anything that is not normal for you.
Coping with side effects
We have more information about side effects and tips on how to cope with them.
What else do you need to know?
Other medicine, food and drink
Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.
Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.
Contraception
This treatment might harm a baby developing in the womb. It is important not to get someone pregnant while you are having treatment and for 2 weeks afterwards. Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if your partner becomes pregnant while you're having treatment.
Loss of fertility
You may not be able to get someone pregnant after treatment with this drug. Talk to your doctor before starting treatment if you think you want to have a baby in the future. You may be able to store sperm before starting treatment.
Treatment for other conditions
If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.
More information about this treatment
For further information about this treatment go to the Medicines Health and Regulatory Authority (MHRA).
You can report any side effect you have to the MHRA as part of their Yellow Card Scheme.
