pronounced as (bel-zoo' ti fan)

Brand Name(s): Welireg®

Why is this medicine prescribed?

Belzutifan is used in adults with von Hippel-Lindau disease (VHL; a rare disease that causes tumors and cysts) to treat renal cell carcinoma (RCC; kidney cancer), central nervous system (CNS) hemangioblastomas (tumors in the brain and spinal cord), and a certain type of pancreatic cancer that does not require surgery right away. Belzutifan is also used to treat certain types of RCC in adult patients. Belzutifan is in a class of medications called hypoxia-inducible factor inhibitors. It works by blocking the activity of a certain protein in people with VHL.

Are there other uses for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Belzutifan comes as a tablet to take by mouth. It is usually taken once daily with or without food. Take belzutifan at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take belzutifan exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole; do not split, chew, or crush them.

If you vomit after taking belzutifan, do not take another dose. Continue your regular dosing schedule on the next day.

Your doctor may temporarily or permanently stop your treatment or decrease your dose if you experience certain side effects. Be sure to tell your doctor how you are feeling during your treatment with belzutifan. Continue to take belzutifan even if you feel well. Do not stop taking belzutifan without talking to your doctor.

What special precautions should I follow?

Before taking belzutifan,

  • tell your doctor and pharmacist if you are allergic to belzutifan, any other medications, or any of the ingredients in belzutifan tablets. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking belzutifan. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had anemia (a lower than normal number of red blood cells).
  • tell your doctor if you are breastfeeding. You should not breast-feed while you are taking belzutifan and for 1 week after your final dose.
  • you should know that this medication may decrease fertility in men and women. Talk to your doctor about the risks of taking belzutifan.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget to take a dose?

Take the missed dose as soon as you remember it on the same day, then continue your regular dosing schedule the next day. Do not take a double dose to make up for a missed one.

What should I do in case of overdose?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at . If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

  • bluish color in skin, nails, and lips
  • shortness of breath or fast heartbeat

What side effects can this medicine cause?

Belzutifan may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • dizziness
  • tiredness
  • headache
  • nausea
  • constipation
  • stomach pain
  • joint or muscle pain
  • vision changes
  • weight gain
  • fever, cough, shortness of breath, or other signs of infection

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

  • tiredness, feeling cold, pale skin, shortness of breath, chest pain, or fast heartbeat

Belzutifan may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( ) or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Keep the two desiccant (drying agent) canisters in the bottle of medication to keep the tablets dry. Do not eat the desiccant canisters.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( ) for more information if you do not have access to a take-back program.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests before and during your treatment to check your body's response to belzutifan.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

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