Selpercatinib (Retevmo®)

Store your medication in the original container with the label. If you want to use a pillbox, talk to your pharmacist. Keep it in a dry place at room temperature unless your provider or pharmacist tells you otherwise. 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 people 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 in the trash. 

Some cancer medications are only available through specialty pharmacies. Your provider or pharmacist will start this process. Your insurance plan may also affect where you can get your medication.  Call your prescription plan provider to find out which specialty pharmacies are in-network.

This medication may be covered by your prescription plan. If you qualify, you may be able to get financial help through patient assistance programs (PAP). Co-pay cards may also be available to lower your out-of-pocket cost if you have commercial (not Medicare/Medicaid/Tricare) insurance. Your pharmacist, social worker, or navigator can help find resources for financial support.

These are some of the most common or most serious side effects of this medication. Talk with your provider about the side effects you are having and how they can be managed.

This medication can cause liver toxicity, or liver problems, which your provider may monitor for with blood tests called liver function tests. Symptoms may be:

• Yellowing of your skin or eyes.
• Dark or brown urine.
• Pain in your abdomen (belly).

Tell your provider if you have any of these symptoms.

This medication can cause high blood sugar in patients with and without diabetes. Symptoms can be:

• Feeling more thirsty.
• More frequent urination.
• Feeling hungrier. 
• Blurry vision.
• Headaches.
• Breath smelling like fruit.

All patients will have their blood sugar checked with blood tests. If you have diabetes and your blood sugars are higher than normal, talk to your provider. Tell your provider if you have any of these symptoms.

White blood cells (WBC) help your body fight infection. While you are having treatment for cancer, your WBC count can drop, putting you at a higher risk of an infection. Tell your provider right away if you have a fever (temperature greater than 100.4°F or 38°C), sore throat or cold, shortness of breath, cough, burning with urination, or a sore that doesn't heal.

Tips for preventing infection:

• Hand washing: both yours and your visitors is the best way to prevent the spread of infection.
• Avoid large crowds and people who are sick (those who have a cold, fever, or cough, or live with someone with these symptoms).
• When working outside, wear clothes that protect you, like long pants and gloves.
• Do not handle pet waste.
• Keep all cuts and scratches clean.
• Shower or bathe daily. 
• Brush your teeth at least twice a day.
• Do not cut cuticles or ingrown nails. You may wear nail polish, but not fake nails.
• Ask your providers before scheduling dental appointments or procedures.
• Ask your providers before you or someone you live with has any vaccines. 

Platelets are blood cells that help your blood clot. Thrombocytopenia is when your platelet count is lower than normal, and you are at a higher risk of bleeding. Tell your providers if you have any bruising or bleeding, including nose bleeds, bleeding gums, or blood in your urine or stool. If your count gets too low, you may receive platelets from a donor. 

• Do not use a razor (an electric razor is fine).
• Do not do activities that can cause injury or bleeding.
• Talk to your provider before taking any non-steroidal, anti-inflammatory medications (NSAIDs) like Motrin/Advil (ibuprofen), Aleve (naproxen), Celebrex (celecoxib), and others. These can raise the risk of bleeding. 
• Use a soft-bristle toothbrush to brush your teeth. Ask your provider about flossing or using toothpicks. 

This medication can affect your electrolytes (potassium, magnesium, sodium, calcium, etc.). Your electrolyte levels will be checked with blood tests. If your levels get too low, you may be given electrolytes by IV (intravenously through your vein) or by mouth. Talk to your provider before taking any supplements. 

Xerostomia is dry mouth. Dry mouth can be uncomfortable and affect your speech, swallowing, and dental health. Here are some ways to manage:

• Brush your teeth often with fluoride toothpaste.
• Floss once a day, if your provider says you can.
• Chew sugar-free gum or suck on sugar-free candy to help make saliva.
• Rinse your mouth often to keep it moist.
• Ask about gels and rinses that help you make more saliva.

Talk to your provider if you start or continue to have xerostomia. 

This medication can cause kidney problems, like an increased creatinine level. Your provider may monitor for kidney problems with blood tests. Symptoms may be:

• Less urine output than normal.
• Blood in the urine.
• Swelling in the ankles.
• Loss of appetite.

Tell your provider if you have any of these symptoms.

Diarrhea is when you pass three or more stools in a day. Your providers can suggest medications to relieve diarrhea. Do not take any medications to manage your diarrhea without talking to your provider first, as your stool may need to be tested. To manage it, try eating foods that are low in fiber and bland, like white rice and boiled or baked chicken. Try not to eat raw fruits, vegetables, whole grain breads, cereals, and seeds. Soluble fiber is a type of fiber found in some foods that helps absorb (soak up) fluid. Foods high in soluble fiber are applesauce, bananas (ripe), canned fruit, oranges, boiled potatoes, white rice, foods made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Stay hydrated by drinking 8 to 10 glasses of non-alcoholic, non-caffeinated fluid each day.

This medication can cause high blood pressure (hypertension). You should have your blood pressure checked often during therapy, so that if you have high blood pressure, it can be treated. If your blood pressure cannot be controlled, your provider may want you to stop taking the medication. Tell your providers about any headaches, vision changes, or dizziness. 

Fatigue can cause exhaustion, feeling worn out and that your body is "heavy" and hard to move, or being unable to focus. It is common when you have cancer, and it is not the same as feeling tired. You may need to adjust your schedule to manage fatigue. Plan times to rest during the day and save your energy for more important activities. Exercise can help lessen fatigue. Talk to your providers about ways to deal with this side effect.

When your cholesterol levels are higher than normal, it is called hypercholesterolemia. There are no symptoms of high cholesterol, but your provider will check your blood levels before, during, and after treatment.

Some people may get a rash, scaly skin, or red, itchy bumps from this medication. Tell your provider if you notice any of these changes in your skin, since it could be a reaction. Your provider may suggest:

• Using an alcohol-free moisturizer on your skin and lips, and do not use moisturizers with perfumes or scents. 
• Keep the area clean to avoid infection, especially if it cracks or bleeds.
• Using a topical medication (applied to the skin) if the itching bothers you.

Be sure to talk with your provider about how to care for your skin.

Constipation is when you have less bowel movements than usual or are having trouble passing stool. To relieve constipation, you can include fiber in your diet (fruits like prunes, apples, peaches, and pear nectars/juices), drink 8 to 10 glasses of non-alcoholic fluids a day, and stay active. Taking a stool softener once or twice a day can prevent constipation. If you do not have a bowel movement for 2 to 3 days, call your provider. 

Talk to your providers if you have nausea and/or vomiting. They can prescribe medications to help you. Making changes to your diet can also help. Avoid things that make your symptoms worse, like heavy or greasy/fatty foods and spicy or acidic foods, like tomatoes, lemons, and oranges. Try saltines or ginger ale to help your symptoms.  

Call your providers if you cannot keep fluids down for more than 12 hours or if you feel lightheaded or dizzy.

This medication may affect your fertility. It can cause changes to your menstrual cycle or sperm. You may want to consider sperm banking or egg harvesting if you might wish to have a child in the future. Talk about your options with your provider before treatment.

There is a higher risk of health problems for your baby if you are pregnant, become pregnant, or get someone pregnant while on this medication. To lower the risk of birth defects, you should use birth control (contraception) to avoid pregnancy. Talk with your provider about what kind of birth control is safest for you and your partner.

QT prolongation is when your heart is not working how it should, and it can cause slow or abnormal heartbeats or an abnormal heart rhythm. Tell your provider right away if you feel abnormal heartbeats or if you feel dizzy or faint.

If you notice you are bleeding more easily or for no reason, especially new bleeding from your gums or nose, call your provider right away. You may also bruise more easily.

If you have bright red or dark, tarry stool, blood in your vomit, vomit that looks like coffee grounds, or have any signs of stroke (severe headache, trouble talking, weakness on one side, confusion), call 911 right away. 

Some people may have an allergic reaction to this medication. Signs of an allergic reaction are:

• Shortness of breath or trouble breathing.
• Chest pain.
• Rash.
• Itching.
• Flushing (reddening of the skin, often on the face, neck, or chest).
• A drop in blood pressure (you may feel lightheaded, dizzy, or weak).

If you have any of these signs while you are getting an infusion, tell your provider right away. The infusion will be slowed down or stopped. Depending on your reaction, you may still be able to get the medication if you are given medicine to prevent a reaction or if the medication is given at a slower rate.

If you have a wound, this medication can affect how it heals. It can make your wound heal very slowly or not heal completely (like a surgical wound not healing or not staying closed). If you are having a procedure or surgery:

• Tell your provider that you have a surgical procedure planned.
• Tell the surgeon that you are taking this medication.
• This medication will likely be stopped before you have any surgery. 
• Any surgical incision should be fully healed before starting or restarting this medication. 

If you have a surgical wound that has not healed or starts to have signs of infection (redness, swelling, warmth), tell your provider.

Tumor Lysis Syndrome (TLS) is a side effect that happens when tumor cells die too quickly, and their waste overwhelms the body. You may be given a medication (allopurinol) and IV fluids to help prevent this. TLS can affect your kidney function. Your provider will monitor your kidney function with blood work. Symptoms may be:

• Nausea.
• Vomiting.
• Diarrhea.
• Lethargy (feeling tired, drowsy, sluggish).
• Little or no urine output.

Tell your provider right away if you have any of these symptoms.

This medication can cause inflammation (swelling and irritation) of your lungs, called pneumonitis. It can also cause scarring of your lungs, called interstitial lung disease. If you have any new or worsening symptoms, like shortness of breath, cough (with or without mucous), fever, or chest pain, call your provider right away. If you are finding it hard to breathe, call 911 right away.

Your thyroid is a gland that makes hormones. This medication can cause hypothyroidism (when your thyroid does not work as well as it should). Your provider will do blood tests to check your thyroid and treat this side effect if you have it. Symptoms of hypothyroidism include:

• Feeling cold.
• Weight gain.
• Feeling anxious.
• Changes in your voice.
• Muscle cramps.

Talk to your provider about any symptoms you are having.