The combination of tezacaftor and ivacaftor is used along with ivacaftor to treat certain types of cystic fibrosis (an inborn disease that causes problems with breathing, digestion, and reproduction) in adults and children 6 years of age and older. Tezacaftor and ivacaftor should be used only in people with a certain genetic make-up. Your doctor may order a blood test to help decide if this medication is right for you. Tezacaftor is in a class of medications called cystic fibrosis transmembrane conductance regulator (CFTR) correctors. Ivacaftor is in a class of medications called cystic fibrosis transmembrane conductance regulator (CFTR) potentiators. Both of these medications work by improving the function of a protein in the body to decrease the build-up of thick mucus in the lungs and improve other cystic fibrosis symptoms.

The combination of tezacaftor and ivacaftor and ivacaftor come as tablets to take by mouth. This medication comes in a package with 4 weeks of medication. Each daily dose has different types of tablets: one tablet is the combination of tezacaftor and ivacaftor and the other tablet is ivacaftor. Take tezacaftor and ivacaftor (1 yellow tablet) every morning with a fatty food and ivacaftor (1 blue tablet) every evening with a fatty food, 12 hours apart. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take these medications exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole; do not split, chew, or crush them.

Take the combination of tezacaftor and ivacaftor and ivacaftor with fatty foods such as eggs, butter, nuts, peanut butter, cheese pizza, and whole-milk dairy products (such as whole milk, cheese, and yogurt). Talk to your doctor about other fatty foods to eat with these medications.

The combination of tezacaftor and ivacaftor along with ivacaftor works to control cystic fibrosis, but they do not cure it. Continue to take these medications even if you feel well. Do not stop taking these medications without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

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

Before taking the tezacaftor and ivacaftor,

• Tell your doctor and pharmacist if you are allergic to tezacaftor, ivacaftor, any other medications, or any of the ingredients in tezacaftor and ivacaftor and ivacaftor tablets. Ask your pharmacist for a list of the ingredients.
• Tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, you are taking or plan to take. Be sure to mention any of the following: certain antibiotics such as clarithromycin (Biaxin, in PrevPac), erythromycin (E.E.S., E-Mycin, Ery-Tab, Erythrocin), and telithromycin (Ketek); certain antifungals such as fluconazole (Diflucan), itraconazole (Onmel, Sporanox), ketoconazole, posaconazole (Noxafil), and voriconazole (Vfend); cyclosporine (Gengraf, Neoral, Sandimmune); digoxin (Lanoxin); everolimus (Afinitor, Zortress); certain medications for seizures such as carbamazepine (Carbatrol, Epitol, Tegretol, others), phenobarbital, and phenytoin (Dilantin, Phenytek); rifabutin (Mycobutin); rifampin (Rifadin, in Rifamate, in Rifater, Rimactane); sirolimus (Rapamune); or tacrolimus (Astagraf, Prograf). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with tezacaftor and ivacaftor, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
• Tell your doctor what herbal products you are taking, especially St. John’s wort. Your doctor will probably tell you not to take St. John’s wort while taking the combination of tezacaftor and ivacaftor along with ivacaftor.
• Tell your doctor if you have or have ever had kidney or liver disease.
• Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking the combination of tezacaftor and ivacaftor along with ivacaftor, call your doctor.
• You should know that these medications may make you drowsy. Do not drive a car or operate machinery until you know how these medications affect you.

Do not eat grapefruit or Seville oranges or drink grapefruit juice while taking these medications.

If you remember the missed dose of either tablet within 6 hours of the time you were scheduled to take it, take the missed dose right away with a fat-containing food. However, if more than 6 hours have passed since the scheduled time to take either tablet, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Tezacaftor and ivacaftor may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• Headache
• Nasal congestion
• Dizziness

Some side effects can be serious. If you experience any of these symptoms, stop taking tezacaftor and ivacaftor and call your doctor immediately:

• Yellowing of the skin or eyes
• Loss of appetite
• Nausea
• Vomiting
• Pale stools
• Stomach pain
• Dark urine

Tezacaftor and ivacaftor may cause cataracts (clouding of the lens of the eye that may cause vision problems) in children and teenagers. Children and teenagers taking tezacaftor and ivacaftor should see an eye doctor before and during their treatment. Talk to your child’s doctor about the risks of giving tezacaftor and ivacaftor to your child.

Tezacaftor and ivacaftor may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Keep all appointments with your doctor and the laboratory. Your doctor will order an eye exam (for children and teenagers) and certain lab tests before and during your treatment to check your body’s response to tezacaftor and ivacaftor.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.