Ivacaftor belongs to the class of medications called cystic fibrosis transmembrane conductance regulator (CFTR) potentiators. It is used to treat cystic fibrosis (CF) for adults and children over the age of 2 months who have one of several possible mutations (a change) in their CFTR gene. It is not effective for people with CF who have the mutation delta F508.

In CF, an abnormal protein called CFTR is produced. This protein changes the way chloride (a component of salt, which is also called sodium chloride) moves in and out of cells. This affects the balance between salt and water in the body, making the mucus that lines the lungs, pancreas, and other organs thicker and stickier. Ivacaftor allows more chloride to be moved and improves the balance between salt and water.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual dose for adults and children (over the age of 6 months and weighing more than 25 kg), is 150 mg twice a day (morning and evening about 12 hours apart) with a fat-containing food. Fat-containing food helps get the right amount of medication into your body. Examples include meals or foods prepared with butter or oils, eggs, cheeses, nuts, whole milk, or meats. Meals and snacks recommended in CF guidelines contain the right amounts of fat.

The usual dose for children more than 2 months of age and weighing between 3 kg and 25 kg, is based on body weight. The prescribed dose should be given every 12 hours. Oral granules are available for children or individuals who have difficulty swallowing tablets. The granules may be sprinkled on soft foods or liquids (excluding grapefruit juice) and consumed within 1 hour. The granules should be consumed with or immediately after a fat-containing food.

Tablets should be swallowed whole with fluids and not chewed, crushed, or dissolved.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken exactly as prescribed by your doctor.

If you miss a dose by less than 6 hours, take the missed dose with fat-containing food, and continue with your regular schedule. If you miss a dose by 6 or more hours, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, and keep it out of the reach of children.

Tablet

Each light-blue, capsule-shaped, film-coated tablet, printed with "V 150" in black ink on one side, contains 150 mg of ivacaftor. Nonmedicinal ingredients: carnauba wax, colloidal silicon dioxide, croscarmellose sodium, hypromellose acetate succinate, indigo carmine aluminum lake, lactose monohydrate, magnesium stearate, microcrystalline cellulose, PEG 3350, polyvinyl alcohol, sodium lauryl sulfate, talc, and titanium dioxide. Printing ink: ammonium hydroxide, iron oxide black, propylene glycol, and shellac.

Oral Granules

13.4 mg
Each packet of white-to-off-white, sweetened, unflavoured granules contains 13.4 mg of ivacaftor. Nonmedicinal ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose acetate succinate, lactose monohydrate, magnesium stearate, mannitol, sucralose, and sodium lauryl sulfate.

25 mg
Each packet of white-to-off-white, sweetened, unflavoured granules contains 25 mg of ivacaftor. Nonmedicinal ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose acetate succinate, lactose monohydrate, magnesium stearate, mannitol, sucralose, and sodium lauryl sulfate.

50 mg
Each packet of white-to-off-white, sweetened, unflavoured granules contains 50 mg of ivacaftor. Nonmedicinal ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose acetate succinate, lactose monohydrate, magnesium stearate, mannitol, sucralose, and sodium lauryl sulfate.

75 mg
Each packet of white-to-off-white, sweetened, unflavoured granules contains 75 mg of ivacaftor. Nonmedicinal ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose acetate succinate, lactose monohydrate, magnesium stearate, mannitol, sucralose, and sodium lauryl sulfate.

Do not take this medication if you are allergic to ivacaftor or any ingredients of the medication.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• diarrhea
• dizziness
• headache
• joint pain
• nausea
• pain in your stomach
• symptoms of an upper respiratory tract infection (the common cold) such as sore throat, nasal or sinus congestion, or a runny nose

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• rash
• signs and symptoms of a liver disorder such as yellowing skin or eyes, dark urine, stomach pain, nausea, vomiting, loss of appetite, pale stools, or itchy skin
• symptoms of low blood sugar (e.g., nervousness, sweating, faintness, fast heartbeat, nausea, tingling, trembling)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• allergic reactions such as rash; hives; swelling of the face, lips, tongue, or throat; difficulty swallowing or breathing

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Cataracts: Some children treated with ivacaftor have developed cataracts. Your doctor may recommend eye examinations before and during treatment with this medication.

Dizziness: Ivacaftor can cause dizziness. Do not drive or operate machinery until you are certain that this medication does not affect your ability to do these activities safely.

Grapefruit juice: Grapefruit juice can increase the levels of ivacaftor in the body, causing side effects. Avoid consuming food or beverages containing grapefruit or grapefruit juice while you are taking ivacaftor.

Kidney function: The safety and effectiveness of ivacaftor have not been established for people with decreased kidney function or end-stage kidney disease. If you have decreased kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition and how your medical condition may affect the dosing and effectiveness of this medication. Your doctor will perform regular tests to check your liver function while you are taking this medication.

Pregnancy: The safety and effectiveness of ivacaftor have not been established for people who are pregnant. This medication should not be used during pregnancy unless the benefits outweigh the risks. Talk to your doctor if you become pregnant while taking this medication.

Breast-feeding: It is not known whether ivacaftor passes into breast milk. If you are breast-feeding and taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of ivacaftor have not been established for children less than 2 months old and weighing less than 3 kg.

Seniors: The safety and effectiveness of ivacaftor have not been established for seniors 65 years of age and older.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.