Ivacaftor

Ivacaftor is a prescription medication used to treat cystic fibrosis. Ivacaftor is for use only in patients who are at least 2 years old, with a specific gene mutation related to cystic fibrosis.

Ivacaftor belongs to a group of drugs 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.

This medication comes in tablet form and is usually taken twice daily, about 12 hours apart, with fatty foods.

Ivacaftor is also available as granules to be mixed with specific foods to be taken by mouth and is usually taken twice daily, about 12 hours apart. Eat fatty foods just before or just after taking the granules.

Common side effects include headaches, colds, stomach pain, and diarrhea.

Ivacaftor is a prescription medicine used for the treatment of cystic fibrosis (CF) in patients age 2 years and older who have at least one mutation in their CF gene that is responsive to this medication. 

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

Ivacaftor may be found in some form under the following brand names:

• Kalydeco

Ivacaftor can cause serious side effects. See "Drug Precautions".

The most common side effects include:

• headache
• upper respiratory tract infection (common cold), including:
  • sore throat
  • nasal or sinus congestion
  • runny nose
• stomach (abdominal) pain
• diarrhea
• rash
• nausea
• dizziness

Tell your doctor if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of ivacaftor. For more information, ask your doctor or pharmacist.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements as the dose of ivacaftor may need to be adjusted when taken with certain medications.

Ask your doctor or pharmacist for a list of these medicines if you are not sure.

Especially tell your doctor if you take:

• antifungal medications such as ketoconazole (e.g., Nizoral), itraconazole (e.g., Sporanox), posaconazole (e.g., Noxafil), voriconazole (e.g., Vfend), or fluconazole (e.g., Diflucan)
• antibiotics such as telithromycin (e.g., Ketek), clarithromycin (e.g., Biaxin), or erythromycin (e.g., Ery-Tab)
• the antibiotics rifampin (Rifamate, Rifater) or rifabutin (Mycobutin)
• seizure medications such as phenobarbital, carbamazepine (Tegretol, Carbatrol, Equetro) or phenytoin (Dilantin, Phenytek)
• St. John’s wort

Know the medicines you take. Keep a list of them to show your doctor and pharmacist when you get a new medicine.

Ivacaftor can cause serious side effects which include:

• High liver enzymes in the blood have been reported in patients receiving ivacaftor. Your doctor will do blood tests to check your liver:
  • before you start ivacaftor
  • every 3 months during your first year of taking this medication
  • every year while you are taking ivacaftor

Call your doctor right away if you have any of the following symptoms of liver problems pain or discomfort in the upper right stomach area, yellowing of your skin or the white part of your eyes, loss of appetite, nausea or vomiting, or dark, amber-colored urine. 

• Cataracts (problems with the eye lens). Cataracts have been seen in some children and adolescents receiving this medication. Your doctor will perform eye examinations prior to and during treatment with this medication to look for cataracts.

Do not take this medication if you are allergic to Kalydeco or allergic to any of its ingredients. 

Ivacaftor can cause dizziness in some people who take it. Do not drive a car, use machinery or do anything that needs you to be alert until you know how it affects you.

Avoid food containing grapefruit or Seville oranges while you are taking ivacaftor.

Grapefruit and Seville oranges may interact with ivacaftor and cause potentially dangerous effects. Avoid food containing grapefruit or Seville oranges while you are taking ivacaftor. Discuss the use of these products with your doctor.

Before you take ivacaftor, tell your doctor if you:

• are allergic to ivacaftor or allergic to any of its ingredients 
• have liver or kidney problems
• drink grapefruit juice, or eat grapefruit or Seville oranges
• are pregnant or plan to become pregnant. 
• are breastfeeding or planning to breastfeed

Ivacaftor may affect the way other medicines work, and other medicines may affect how ivacaftor works.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements as the dose of ivacaftor may need to be adjusted when taken with certain medications.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Ivacaftor falls into category B. There are no well-done studies that have been done in humans with ivacaftor. But in animal studies, pregnant animals were given this medication, and the babies did not show any medical issues related to this medication.

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if ivacaftor crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, a choice should be made whether to stop nursing or stop the use of this medication. Your doctor and you will decide if the benefits outweigh the risk of using ivacaftor.

• Take ivacaftor exactly as your doctor tells you to take it.
• Ivacaftor comes in tablet form and granules to be taken by mouth. 
• Your doses of ivacaftor should be taken 12 hours apart.
• If you miss a dose of ivacaftor and it is within 6 hours of when you usually take it, take your dose of ivacaftor as prescribed with fat-containing food as soon as possible.
• If you miss a dose of  ivacaftor and it is more than 6 hours after the time you usually take it, skip that dose only and take the next dose when you usually take it. Do not take 2 doses at the same time to make up for your missed dose. 

Ivacaftor Tablets (ages 6 years and older):

• Always take ivacaftor tablets with food that contains fat. Examples of fat-containing foods include eggs, butter, peanut butter, cheese pizza, and whole-milk dairy products such as whole milk, cheese, and yogurt.

Ivacaftor Oral Granules (ages 2 to under 6 years old):

•  Hold the packet with cut line on top.
• Shake the packet gently to settle the ivacaftor granules. 
• Tear or cut packet open along cut line.
• Carefully pour all of the ivacaftor granules in the packet into 1 teaspoon of soft food or liquid. Food or liquid should be at or below room temperature. Some examples of soft foods or liquids include puréed fruits or vegetables, yogurt, applesauce, water, milk, or juice.
• Mix the ivacaftor granules with food or liquid.
• After mixing, give ivacaftor within 1 hour. Make sure all medicine is taken.
• Give a child fat-containing food just before or just after the ivacaftor granules dose. Examples of fat containing foods include eggs, butter, peanut butter, cheese pizza, and whole-milk dairy products such as whole milk, cheese, and yogurt.

Take ivacaftor exactly as prescribed. Follow the directions on your prescription label carefully.

The recommended dose of ivacaftor for both adults and pediatric patients age 6 years and older is one 150 mg tablet taken orally every 12 hours (300 mg total daily dose) with fat-containing food. 

The recommended dose of ivacaftor in children 2 to less than 6 years of age and less than 14 kg is one 50 mg packet mixed with 1 teaspoon (5 mL) of soft food or liquid and administered orally every 12 hours with fat-containing food.

The recommended dose of ivacaftor in children 2 to less than 6 years of age and 14 kg or greater is one 75 mg packet mixed with 1 teaspoon (5 mL) of soft food or liquid and administered orally every 12 hours with fat-containing food. 

Your doctor may reduce your dose if you have liver disease or are taking certain medications. 

If you take too much ivacaftor, call your local Poison Control Center or seek emergency medical attention right away.

• Store ivacaftor at room temperature between 68°F to 77°F (20°C to 25°C).
• Do not use ivacaftor after the expiration date on the package.

Keep ivacaftor and all medicines out of the reach of children.