Ivacaftor

Ivacaftor is used to treat certain types of cystic fibrosis (an inborn disease that causes problems with breathing, digestion, and reproduction) in adults and children 1 month of age and older. Ivacaftor should be used only in people with a certain genetic make-up. Your doctor may order a blood test to help decide if this medication is right for you. Ivacaftor is in a class of medications called cystic fibrosis transmembrane conductance regulator (CFTR) potentiators. It works by improving the function of a protein in the body to decrease the build-up of thick mucus in the lungs and improving other symptoms of cystic fibrosis.

Ivacaftor comes as a tablet and as granules to take by mouth. It is usually taken with fatty foods twice a day, 12 hours apart. Take ivacaftor at around the same times 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 ivacaftor 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.

To prepare a dose of ivacaftor granules, mix the entire packet of granules in 1 teaspoon (5 mL) of cold or room temperature soft food or liquid such as yogurt, applesauce, water, milk, baby formula, breast milk, or juice. Take the mixture within 1 hour of mixing the granules with food or a liquid.

Take each dose of ivacaftor with a fatty food such as eggs, butter, peanut butter, cheese pizza, whole-milk dairy products (such as whole milk, cheese, and yogurt), baby formula, and breast milk. Talk to your doctor about other fatty foods to eat with ivacaftor.

Ivacaftor controls cystic fibrosis but does not cure it. Continue to take ivacaftor even if you feel well. Do not stop taking ivacaftor without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

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

Before taking ivacaftor,

• tell your doctor and pharmacist if you are allergic to ivacaftor, any other medications, or any of the ingredients in ivacaftor tablets or granules. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• the following nonprescription or herbal products may interact with ivacaftor: St. John's wort. Be sure to let your healthcare provider know that you are taking this medication before you start taking ivacaftor. Do not start this medication while taking ivacaftor without talking to your healthcare provider.
• tell your doctor if you have or have ever had liver or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking ivacaftor, call your doctor.
• you should know that ivacaftor may make you dizzy. Do not drive a car or operate machinery until you know how this medication affects you.

Do not eat grapefruit or drink grapefruit juice while taking this medication.

If you remember the missed dose within 6 hours of the time you were scheduled to take it, take the missed dose right away with a fat-containing food. However, if more than 6 hours have passed since the scheduled time, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

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

• headache
• rash
• joint or muscle pain
• mouth and throat pain
• fever, sore throat, runny nose, or other signs of infection
• diarrhea
• dizziness

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

• nausea
• vomiting
• loss of appetite
• pain in the upper right part of the stomach
• dark urine
• extreme tiredness
• unusual bleeding or bruising
• yellowing of the skin or eyes
• vision changes
• rash; hives; itching; swelling of the face, eyes, lips, tongue, mouth, or throat; wheezing; difficulty breathing or swallowing; or lightheadedness

Ivacaftor maycause cataracts (clouding of the lens of the eye that may cause vision problems) in children and teenagers. Talk to your doctor or your child's doctor about the risks of taking this medication.

Ivacaftor 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 (https://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

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).

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. https://www.upandaway.org

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 (https://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

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

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

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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