ivacaftor and tezacaftor

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

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 tezacaftor?

Ivacaftor and tezacaftor is a combination medicine used to treat cystic fibrosis in adults and children who are at least 6 years old.

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

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

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

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

• St. John's wort;
• seizure medicine --carbamazepine, phenobarbital, phenytoin; or
• tuberculosis medicine --rifabutin, rifampin.

Tell your doctor if you have ever had:

• liver disease; or
• kidney disease.

Tell your doctor if you are pregnant or breastfeeding.

How should I take ivacaftor and tezacaftor?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Ivacaftor and tezacaftor is supplied as two separate daily tablets. A yellow tablet is taken in the morning and a blue tablet is taken 12 hours later. Follow your doctor's dosing instructions very carefully.

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 tezacaftor?

Grapefruit and Seville oranges may interact with ivacaftor and tezacaftor and lead to unwanted side effects. Avoid the use of grapefruit products and orange marmalades.

What are the possible side effects of ivacaftor and tezacaftor?

• vision problems; or
• liver problems --loss of appetite, stomach pain (upper right side), dark urine, jaundice (yellowing of the skin or eyes).

Common side effects may include:

• stuffy nose;
• dizziness;
• nausea; or
• headache.

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 tezacaftor?

Your doctor may adjust your ivacaftor and tezacaftor dose if you also use other medicines, especially:

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

This list is not complete. Other drugs may affect ivacaftor and tezacaftor, 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 tezacaftor.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2023 Cerner Multum, Inc. Version: 3.01. Revision date: 2/12/2021.