ivacaftor and lumacaftor

What is the most important information I should know about ivacaftor and lumacaftor?

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact, and some drugs should not be used together.

What is ivacaftor and lumacaftor?

Ivacaftor and lumacaftor is a combination medicine used to treat cystic fibrosis in adults and children who are at least 2 years old.

Ivacaftor and lumacaftor is for use only in patients with a specific gene mutation related to cystic fibrosis. Before you take this medicine, you may need a medical test to make sure you have this gene mutation.

Ivacaftor and lumacaftor may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking ivacaftor and lumacaftor?

Some medicines can cause unwanted or dangerous effects when used with ivacaftor and lumacaftor. Your doctor may change your treatment plan if you also use:

• St. John's wort;
• medicine to prevent organ transplant rejection --cyclosporine, everolimus (Zortress), sirolimus, tacrolimus;
• a sedative --triazolam or midazolam;
• seizure medicine --carbamazepine, phenobarbital, phenytoin; or
• tuberculosis medicine --rifabutin, rifampin.

Tell your doctor if you have ever had:

• liver disease;
• kidney disease;
• high blood pressure;
• asthma or other lung disease; or
• an organ transplant.

Tell your doctor if you are pregnant or breastfeeding.

How should I take ivacaftor and lumacaftor?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

To use the oral granules: Mix the granules with 1 teaspoon of milk, juice, or soft food such as applesauce, yogurt, or pudding. The food or liquid should be at or below room temperature. Mix only 1 dose at a time, and use the mixture within 1 hour after mixing. Feed the child a high-fat food just before or just after giving the granule mixture.

Take your doses at regular intervals, 12 hours apart. This will keep a steady amount of the drug in your body at all times.

Ivacaftor and lumacaftor doses are based on age and weight in children. Children from 2 to 5 years old should take oral granules. Children 6 and older should take tablets.

You will need frequent blood tests to check your liver function. Your blood pressure may also need to be checked often.

A child using this medicine may need frequent eye exams to check for cataracts.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if you are more than 6 hours late for the dose. Do not take two doses at one time.

Be sure to take a missed dose with a food that contains fat.

What happens if I overdose?

What should I avoid while taking ivacaftor and lumacaftor?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What are the possible side effects of ivacaftor and lumacaftor?

• shortness of breath, tightness in your chest; or
• liver problems --nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

• breathing problems;
• feeling tired;
• nausea, gas, diarrhea;
• rash;
• flu symptoms;
• changes in your menstrual periods; or
• cold symptoms such as runny or stuffy nose, sinus pain, sore throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect ivacaftor and lumacaftor?

During your first week of using ivacaftor and lumacaftor, your doctor may adjust your dose if you also use other medicines, especially:

• an antibiotic --clarithromycin, erythromycin, telithromycin; or
• antifungal medicine --itraconazole, ketoconazole, posaconazole, voriconazole.

This list is not complete. Other drugs may affect ivacaftor and lumacaftor, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Where can I get more information?

Your pharmacist can provide more information about ivacaftor and lumacaftor.