Enzalutamide (Oral)

Enzalutamide is a chemotherapy drug that is used to treat some forms of metastatic prostate cancer.

Overview

Enzalutamide is sold in the US under the brand name, Xtandi. The medicine comes only on prescription from your treating physician and is available in liquid-filled capsule form.

Enzalutamide is one of a group of cancer drugs called antiandrogens. This medication is used to treat men with prostate cancer that has spread and which has not been successfully treated with other medicines designed to lower testosterone levels in the patient's body.

The medication works by obstructing the effects of testosterone and other androgen hormones, effectively preventing the cancerous cells from growing and spreading.

Conditions treated

  • Metastatic prostate cancer

Type of medicine

  • Antiandrogen
  • Liquid-filled capsules

Side effects

Many drugs can cause unwanted side effects in addition to the effects they are intended to have. Not all these effects will occur, but if they do, they may require further medical attention.

If you notice any of the following side effects after you start using enzalutamide, you should talk to your treating physician immediately:

  • Unexpected weight loss or gain
  • Inability to move the legs
  • Tingling of the feet or hands
  • Sore throat
  • Slow or rapid heartbeat
  • Seizures
  • Rapid or shallow breathing
  • Pounding sensation in the ears
  • Difficult or painful urination
  • Vivid dreams or nightmares
  • Nervousness
  • Attention span or memory problems
  • Loss of bowel or bladder control
  • Feeling lightheaded
  • Fever or chills
  • Falling
  • Fainting
  • Dizziness
  • Difficulty breathing
  • Depression
  • A cough with mucus
  • Confusion or excitement
  • Chest pain
  • Blurred vision
  • Blood in the urine
  • Swelling or bloating of the hands, face, arms, feet, or lower legs
  • Back pain
  • Anxiety

Some people receiving treatment with enzalutamide may experience side effects that resolve by themselves, without the need for any medical attention. If these effects persist or become especially troublesome, have a chat with your treating physician about ways in which the effects can be managed or prevented. These effects can include:

  • Tiredness or weakness
  • Trouble swallowing
  • Problems with sleeping
  • Swollen, tender neck glands
  • Runny or stuffy nose
  • Sensation of spinning
  • Redness of the arms, neck, face, and upper chest
  • Pale-colored urine
  • Pain or tenderness around the cheekbones and eyes
  • Muscle pain, weakness or stiffness
  • Loss of voice
  • Loss of strength
  • Joint pain
  • Itchy skin
  • Hoarseness
  • Frequent urination
  • Feeling of warmth
  • Feeling of constant movement or surroundings or self
  • Ear congestion
  • Dry throat
  • Dry skin
  • Difficulty with mobility
  • Constipation
  • Diarrhea
  • Strange skin sensations, including itching, burning, crawling, numbness, prickling, tingling, or pins and needles'
  • Bone pains
  • Body aches and pains
  • Bloody nose

There may be other effects that you notice that are not mentioned here. If you experience any other side effects, you should speak to your GP.

Dosage

When you collect your prescription of enzalutamide, you will be given a patient medication guide. Read the information contained in the guide and ask your doctor if you have any questions about the contents.

You should take enzalutamide capsules with or without food. Take each capsule whole. Do not open, dissolve, or chew the capsules.

The dose you are prescribed will be based on your medical condition and your body's response to the drug. Other medicines you take will also influence the dose of enzalutamide you are given, so remember to tell your GP about any other prescribed, non-prescription, vitamins, or herbal products that you are using.

You must not increase the amount of this medication you take, take it more often, or use it for longer than you have been told to. This could increase your risk of side effects or overdose and it will not make your condition improve any faster.

If possible, take your enzalutamide capsules at the same time every day. This will ensure that the levels of the drug remain constant in your body, improving its efficacy. If you taking any other cancer medications, be sure to follow your medical practitioner's directions on when to take them.

The dose of enzalutamide that you are prescribed will vary between patients. Take the drug in accordance with your GP's directions or the instructions on the dispensary label. The information contained here is only based on the average for this drug. Do not change your dose if it is different, unless your GP instructs you to.

For prostate cancer oral capsules:

  • Adults: Take four x 40 mg capsules once daily.
  • Children: Dose and use in accordance with your GP's directions.

If you omit a dose of your medicine, try to take the dose without delay. If it's nearly time for your next capsule, leave out one dose and go back to your usual schedule. Never take twice the amount.

Overdose

In the event that you overdose, you may experience breathing difficulties, loss of consciousness, or seizures. In these circumstances, do not wait for a GP appointment; call 911 immediately.

Never share your prescription of enzalutamide with anyone else.

Do not stop taking enzalutamide or reduce the dose, even if you begin to feel much better after a week or so of treatment. Your oncologist will tell you when you can cease using the drug, based on reviews of your progress.

If you begin to feel worse immediately after beginning your course of enzalutamide, or if you do not think that you are getting any better, check with your doctor or treating specialist.

Interactions

Some medicines should never be used together, as this may cause an interaction that could be harmful to the patient. In other cases, it may be appropriate to use two drugs together, even though there may be an interaction between them. Your doctor may decide to change the dose of one or both of your medicines, or may suggest ways in which you can manage the effects of any interaction.

Using enzalutamide with any of the following drugs is not recommended. Tell your doctor if you are already taking any of these medicines:

  • Warfarin
  • Vortioxetine
  • Voriconazole
  • Vorapaxar
  • Vinflunine
  • Vilazodone
  • Venetoclax
  • Vemurafenib
  • Velpatasvir
  • Vandetanib
  • Ulipristal
  • Tofacitinib
  • Ticagrelor
  • Temsirolimus
  • Telithromycin
  • Telaprevir
  • Tasimelteon
  • Tacrolimus
  • St John's Wort
  • Sorafenib
  • Sofosbuvir
  • Sirolimus
  • Saquinavir
  • Romidepsin
  • Ritonavir
  • Rifapentine
  • Rifampin
  • Rifabutin
  • Regorafenib
  • Quinidine
  • Quetiapine
  • Posaconazole
  • Ponatinib
  • Pixantrone
  • Piperaquine
  • Pimozide
  • Phenytoin
  • Perampanel
  • Pazopanib
  • Panobinostat
  • Palbociclib
  • Oxycodone
  • Oxcarbazepine
  • Ospemifene
  • Osimertinib
  • Olaparib
  • Nilotinib
  • Nifedipine
  • Nevirapine
  • Netupitant
  • Nelfinavir
  • Nefazodone
  • Naloxegol
  • Modafinil
  • Mephenytoin
  • Maraviroc
  • Manidipine
  • Macitentan
  • Lurasidone
  • Lumefantrine
  • Lopinavir
  • Linagliptin
  • Ketoconazole
  • Ixazomib
  • Ivabradine
  • Isavuconazonium
  • Indinavir
  • Imatinib
  • Idelalisib
  • Ibrutinib
  • Grazoprevir
  • Gemfibrozil
  • Fosphenytoin
  • Fosaprepitant
  • Fentanyl
  • Exemestane
  • Everolimus
  • Etravirine
  • Erlotinib
  • Ergotamine
  • Eliglustat
  • Elbasvir
  • Efavirenz
  • Doxorubicin Hydrochloride Liposome
  • Doxorubicin
  • Dolutegravir
  • Dihydroergotamine
  • Dexamethasone
  • Delamanid
  • Deferasirox
  • Dasabuvir
  • Daclatasvir
  • Dabrafenib
  • Cyclosporine
  • Crizotinib
  • Conivaptan
  • Cobimetinib
  • Clozapine
  • Clarithromycin
  • Ceritinib
  • Carbamazepine
  • Cabozantinib
  • Bosutinib
  • Bosentan
  • Boceprevir
  • Bedaquiline
  • Axitinib
  • Atazanavir
  • Artemether
  • Aripiprazole
  • Aprepitant
  • Apremilast
  • Alfentanil
  • Abiraterone

You should not use tobacco, alcohol, or eat certain types of foods around the time of taking some drugs. Be sure to discuss your use of this medication with tobacco, alcohol, or food with your GP before you begin taking enzalutamide.

Warnings

Before you begin taking any new medicine, you should weigh the benefits against the risks of doing so. Discuss this aspect of your treatment with your GP, and make a decision based on this discussion.

If you are allergic to enzalutamide or to any form of drug, tell your doctor. This includes non-prescription products, certain food groups, food colors, preservatives, or animal by-products.

Pregnancy

Enzalutamide is known to be harmful to the fetus and exposure to the drug while pregnant can cause birth defects in the baby. This medication can be absorbed into the lungs and through the skin. Women who are pregnant must not handle this medication or inhale any dust that may be emitted from the capsules.

Men who are being treated with this drug must use a condom during sex and for three months following the conclusion of their treatment. If your partner is of childbearing age, she should use an effective form of birth control, as well as condoms, during your treatment and for three months afterwards. If your partner does become pregnant or thinks that she is, you must tell your doctor immediately.

Medical history

Some historical or existing health conditions can affect how enzalutamide works. Have a full and frank discussion with your doctor about your medical history before you begin taking this medication.

If you have a history of any of the following conditions, you should use enzalutamide with caution as its side effects may become worse:

You must attend your GP clinic or oncologist for regular check-up appointments. These visits are necessary to allow your treating physician to make sure that the medication is working as desired and to discuss the management of any unwanted side effects that you may be experiencing.

Long-term use of enzalutamide can cause some patients to experience feelings of fatigue, dizziness, and muscle weakness. In very rare cases, people taking this medication have reported seizures. If this medication affects you in these ways, you must not drive, operate machinery, or undertake any other activity that could be dangerous if you are not fully alert.

Some patients taking enzalutamide may develop a neurological condition called posterior reversible encephalopathy syndrome (PRES). If you notice any of the symptoms listed below, you should speak to your treating physician without delay:

  • Weakness
  • Unusual drowsiness
  • Tiredness
  • Seizures
  • Headache
  • Feeling of sluggishness
  • Dullness
  • Confusion
  • Blurred vision

While you are using enzalutamide, you must not take any other form of medication, unless you have discussed it with your treating physician or oncologist first. This includes other prescribed drugs, over the counter products, herbal or vitamin supplements.

Storage

You should store your enzalutamide capsules in the container they were supplied in, with the lid securely closed. Keep the drug in a location that is not near a heat source or in a place where it will be exposed to direct sunlight.

Do not keep the medicine in a bathroom where it could get wet. Do not put the capsules in a refrigerator or freezer. This medicine should be kept at room temperature.

Make sure that the medicine is in a place where it cannot be reached easily by pets or children. If a pet does consume any of the capsules, contact your emergency vet right away.

Do not keep any enzalutamide capsules that are out of date or that you no longer need. Dispose of unwanted medication responsibly and safely by placing it in a sealed bag or container and putting it at the bottom of your trash can, where children and pets cannot get to it. Alternatively, ask your GP or pharmacist to dispose of the drugs for you.

Summary

Enzalutamide belongs to a class of medicines that are known as antiandrogens. These drugs are used to treat prostate cancer when other medicines have failed to reduce the levels of testosterone in the patient's body.

There is a long list of drugs that may cause an interaction when used together with enzalutamide. There are also a number of medical conditions that can be made worse by using this drug. It is therefore very important that you tell your treating physician about any other medicines you are using, before you start taking enzalutamide.

You must also attend your doctor or oncology specialist for regular reviews. These sessions will allow your doctor to check that the treatment regimen is working effectively, and also gives you an opportunity to mention any strange or unexpected effects that you may have noticed since you began taking the drug.

Enzalutamide can be extremely dangerous to the unborn baby. If your partner is pregnant, you must use a condom during sex. Do not allow your partner to handle your medication. If appropriate, take extra precautions to ensure that you partner does not become pregnant while you are using this medication.