Belzutifan (Welireg™)

How to Take Belzutifan (Welireg™)

This medication comes in tablet form to be taken by mouth. It can be taken with or without food. It should be swallowed whole. It should not be broken, crushed, or chewed. It is usually taken once a day. If you miss a dose, take it as soon as possible that day, then take your next dose at the usual time on the next day. Don’t take extra doses to make up for a missed dose. If you vomit after taking this medication, don’t take an extra dose.

It is important to make sure you are taking the correct amount of medication every time. Before every dose, check that what you are taking matches what you have been prescribed.

Belzutifan can be affected by certain medications. Be sure to tell your provider about all medications and supplements you take. It can also affect how hormonal birth control (pills, some IUD’s, injections, vaginal rings, and skin patches) works, so you should use a non-hormonal method (condom, diaphragm, sponge, copper IUD, cervical cap) of birth control during treatment and for 1 week after the last dose.

Storage and Handling

Store your medication in the original, labeled container at room temperature and in a dry location (unless told to do otherwise by your provider or pharmacist). This medication should not be stored in a pillbox. Keep containers out of reach of children and pets.

If a caregiver prepares your dose for you, they should consider wearing gloves or pour the pills directly from their container into the cap, a small cup, or directly into your hand. They should avoid touching the pills. They should always wash their hands before and after giving you the medication. Pregnant or nursing women should not prepare the dose for you. Ask your provider where to return any unused medication for disposal. Do not flush down the toilet or throw it in the trash.

Where do I get this medication?

Certain cancer medications are only available through specialty pharmacies. If you need to get this medication through a specialty pharmacy, your provider will help you start this process. Where you can fill your prescriptions may also be influenced by your prescription drug coverage. Ask your provider or pharmacist for help in identifying where you can get this medication.

Insurance Information

This medication may be covered under your prescription drug plan. Patient assistance may be available to qualifying individuals depending upon prescription drug coverage. Co-pay cards, which reduce the patient co-pay responsibility for eligible commercially (non-government sponsored) insured patients, may also be available. Your provider can help you find these resources if they are available.

Possible Side Effects of Belzutifan

There are a number of things you can do to manage the side effects of belzutifan. Talk to your provider about these recommendations. They can help you decide what will work best for you. These are some of the most common or important side effects:

Anemia

Your red blood cells are responsible for carrying oxygen to the tissues in your body. When the red cell count is low, you may feel tired or weak. You should let your provider know if you experience any shortness of breath, difficulty breathing, or pain in your chest. If the count gets too low, you may receive a blood transfusion.

Fatigue

Fatigue is very common during cancer treatment and is an overwhelming feeling of exhaustion that is not usually relieved by rest. While on cancer treatment, and for a period after, you may need to adjust your schedule to manage fatigue. Plan times to rest during the day and conserve energy for more important activities. Exercise can help combat fatigue; a simple daily walk with a friend can help. Talk to your provider for helpful tips on dealing with this side effect.

Kidney problems

This medication can cause kidney problems, including an increased creatinine level, which your provider may monitor for using blood tests. Notify your healthcare provider if you notice decreased urine output, blood in the urine, swelling in the ankles, or loss of appetite.

Muscle, Back, or Joint Pain/Aches

This medication can cause joint or muscle aches and pains, which may be treated with medications. Talk with your provider about which pain relievers you can safely take. Non-medical therapies, such as acupuncture, yoga, gentle stretching, and exercise may also help reduce this side effect.

Headache

Your provider can recommend medications and other strategies to help relieve pain.

High Blood Sugar

This medication can cause elevated blood sugar levels in patients with and without diabetes. Your provider will monitor your blood sugar. If you develop increased thirst, urination or hunger, blurry vision, headaches or your breath smells like fruit, notify your provider. Diabetics should monitor their blood sugar closely and report elevations to the provider.

Nausea and/or Vomiting

Talk to your provider so they can prescribe medications to help you manage nausea and vomiting. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy /fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try saltines or ginger ale to lessen symptoms.

Call your provider if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.

Low White Blood Cell Count (Lymphopenia)

White blood cells (WBC) are important for fighting infection. While receiving treatment, your WBC count can drop, putting you at a higher risk of getting an infection. You should let your provider know right away if you have a fever (your provider will tell you at what temperature to call), sore throat or cold, shortness of breath, cough, burning with urination, or a sore that doesn't heal.

Tips for preventing infection:

• Washing hands, both yours and your visitors, is the best way to prevent the spread of infection.
• Avoid large crowds and people who are sick (i.e.: those who have a cold, fever, or cough or live with someone with these symptoms).
• When working in your yard, wear protective clothing including long pants and gloves.
• Do not handle pet waste.
• Keep all cuts or scratches clean.
• Shower or bath daily and perform frequent mouth care.
• Do not cut cuticles or ingrown nails. You may wear nail polish, but not fake nails.
• Ask your provider before scheduling dental appointments or procedures.
• Ask your provider before you, or someone you live with has any vaccinations.

Electrolyte Changes

This medication can affect the normal levels of electrolytes (sodium, potassium, etc.) in your body. Your levels will be monitored using blood tests. If your levels become too low, your provider may prescribe specific electrolytes to be given by IV or taken by mouth. Do not take any supplements without first consulting with your provider.

Vision Changes

This medication can cause blurred vision, retinal detachment, and central retinal vein occlusion. Contact your provider if you have changes in your vision.

Important but Less Common Side Effects

• Hypoxia: When the level of oxygen in your blood (also called oxygen saturation or pulse ox) is too low, it is called hypoxia. Belzutifan can cause hypoxia. Your blood oxygen will be measured with a pulse ox reader on your finger before and during treatment. Let your provider know right away if you are having a hard time breathing or catching your breath, or feel dizzy or lightheaded.

Reproductive Concerns

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective non-hormonal birth control (condoms, diaphragm, copper IUD, cervical cap, and sponge) is necessary during treatment and for at least 1 week after treatment. Even if your menstrual cycle stops or you believe you are not producing sperm, you could still be fertile and conceive. You should not breastfeed while taking this medication or for 1 week after your last dose.