What Is Kalydeco (Ivacaftor)?

Reviewed by: HU Medical Review Board | Last reviewed: May 2022

Kalydeco® (ivacaftor) is approved to treat cystic fibrosis (CF) in people with one of 97 different kinds of CFTR mutations. It can be used by people with CF who are 4 months and older.1

Cystic fibrosis (CF) is a genetically inherited disease that causes recurring lung infections and gastrointestinal issues that gradually damage many organs. People with CF inherit 2 copies of a defective or mutated CF gene, meaning each parent was a carrier for CF.1

The full prescribing information includes a list of all the genetic mutations that Kalydeco is known to treat.

How does Kalydeco work?

In CF, the cystic fibrosis transmembrane conductance regulator (CFTR) gene is abnormal. This mutation affects how the body makes the CFTR protein. A properly made CFTR protein helps cells move chloride, an element in salt, to the cell surface. In CF, the CFTR protein cannot move chloride correctly. Without chloride, water does not move to the cell surface, resulting in a thick, sticky mucus building up in the lungs and other organs.2,3

Kalydeco belongs to a class of drugs called CFTR modulators. These drugs target specific defects in the CFTR protein so that it can work properly.1

Kalydeco is what is called a potentiator (which is a type of modulator). Potentiators are drugs that help chloride flow through the cell membrane. Ivacaftor helps people with cystic fibrosis who have more than 97 different gating and conductive mutations, and a few residual function and splice mutations.1-3

Kalydeco helps more chloride reach the cell surface, which makes the mucus thinner and less sticky. This reduces the symptoms of CF.1-3

Why genetic testing is important in cystic fibrosis

CFTR modulators are designed to correct the specific type of malfunction that certain CF mutations cause. If you do not have one of these mutations, Kalydeco (ivacaftor) will not work to correct why your CFTR protein fails to carry chloride through cells. This is why it is important to know which genetic mutation for CF you have. If you do not know your mutation, the Cystic Fibrosis Foundation offers free genetic testing for people with cystic fibrosis.

What are the possible side effects of Kalydeco?

The most common side effects of Kalydeco include:1

  • Headache
  • Pain in the throat
  • Upper respiratory tract infections, such as colds, nasal and sinus congestion, or runny nose
  • Stomach pain
  • Rash
  • Nausea
  • Dizziness
  • Diarrhea

These are not all of the possible side effects of Kalydeco. Talk to your doctor about what to expect or if you experience any changes that worry you.

Things to know about Kalydeco

Kalydeco may affect a person’s eyesight or increase their risk of cataracts, an adverse event in pediatric patients. People taking it should get regular eye exams to watch for the development of cataracts.1

Kalydeco may be combined with other CFTR modulators to treat people with other types of CFTR protein mutations.3

Doctors do not know yet if Kalydeco is safe to take during pregnancy or while breastfeeding. Before using this drug, tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding.1

Ivacaftor should not be given to children younger than 6 months if they have liver problems.1

Kalydeco should not be taken with CYP3A inducers such as rifampin and St. John’s wort. These products make ivacaftor less effective. Before taking Kalydeco, tell your doctor about any other medicines you take, including over-the-counter vitamins and supplements.1

Kalydeco can affect liver function in some people. Your doctor will check your liver function before starting Kalydeco and at regular intervals while on the drug.1

For more information, read the full prescribing information of Kalydeco.

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