This is a combination product that contains two medications: ivacaftor and tezacaftor. It is used to treat cystic fibrosis (CF) in adults and adolescents over the age of 12 who have one of several possible mutations (a change) in their CFTR gene, the F508del mutation. 

Ivacaftor belongs to the class of medications called cystic fibrosis transmembrane conductance regulator (CFTR) potentiators. It increases the movement of chloride into and out of cells. Tezacaftor belongs to the class of medications called cystic fibrosis transmembrane conductance regulator (CFTR) correctors. It is believed to work by correcting the shape of the mutated CFTR gene and thereby make more protein that works correctly at the cell wall.

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. Tezacaftor helps get more CFTR proteins to the cell surface and ivacaftor helps the CFTR proteins at the cell surface work better.

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 recommended dose of this medication is one combination tablet (tezacaftor 100 mg/ivacaftor 150 mg) taken by mouth in the morning and one tablet of ivacaftor 150 mg taken in the evening.

This medication should be taken with a fat-containing food. Fat-containing food helps get the right amount of medication into your body. Examples include butter or oils, eggs, cheeses, nuts, whole milk, or meats. Meals and snacks recommended in CF guidelines contain the right amounts of fat.

 Doses should be spread approximately 12 hours apart. Swallow the tablets whole with some fluid. Do not break, crush, or chew the tablets. Do not consume food or drinks containing grapefruit or Seville oranges while taking this medication.

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 to take this medication exactly as prescribed by your doctor.

If you miss a dose, and it is less than 6 hours since the missed dose, take it as soon as possible with fat-containing food and continue with your regular schedule. If it less than 6 hours until your next dose, 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, protect it from light and moisture, and keep it out of the reach of children.

Morning Tablet
Each yellow, capsule-shaped tablet debossed with "V100" on one side and plain on the other contains 100 mg of tezacaftor and 150 mg of ivacaftor. Nonmedicinal ingredients: croscarmellose sodium, hypromellose, hypromellose acetate succinate, magnesium stearate, microcrystalline cellulose, sodium lauryl sulfate; Film coating: HPMC/hypromellose 2910, hydroxypropyl cellulose, iron oxide yellow, talc, and titanium dioxide; Printing Ink: ammonium hydroxide, iron oxide black, and propylene glycol, shellac.  

Evening Tablet
Each light blue, capsule-shaped tablet, printed with "V150" in black ink on one side and plain on the other, contains 150 mg of ivacaftor. Nonmedicinal ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose acetate succinate, lactose monohydrate, magnesium stearate, microcrystalline cellulose, and sodium lauryl sulfate; Film coating: carnauba wax, FD&C Blue #2, PEG 3350, polyvinyl alcohol, talc, and titanium dioxide; Printing Ink: ammonium hydroxide, iron oxide black, and propylene glycol, shellac.

Do not take this medication if you are allergic to tezacaftor, 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.

• cold symptoms (runny nose, nasal congestion, cough)
• dizziness
• headache
• nausea
• signs and symptoms of a liver problems such as yellowing skin or eyes, dark urine, stomach pain, nausea, vomiting, loss of appetite, pale stools, or itchy skin

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

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

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: Cataracts have been reported in children treated with ivacaftor without tezacaftor. Your doctor may recommend eye examinations before and during treatment with this medication.

Dizziness: Tezacaftor - ivacaftor may cause dizziness, affecting your ability to drive or operate machinery. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how you are affected by this medication.

Kidney function: The safety and effectiveness of tezacaftor - ivacaftor have not been established for people with decreased kidney function or end-stage kidney disease. If you have severely 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: People taking tezacaftor - ivacaftor may have changes in liver function that produce abnormal liver test results. Your doctor may recommend regular liver tests while you are taking this medication. If you have severe changes in liver function, your doctor may recommend that you take a lower dose of this medication or stop taking it altogether.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Pregnancy: The safety and effectiveness of tezacaftor - ivacaftor have not been established for women 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 or tezacaftor pass into breast milk. If you are a breast-feeding mother and are 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 tezacaftor - ivacaftor have not been established for children less than 12 years old.

There may be an interaction between tezacaftor - ivacaftor and any of the following:

• aliskiren
• amiodarone
• apalutamide
• aprepitant
• aripiprazole
• "azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
• bicalutamide
• bosentan
• calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
• cancer medications (e.g., daunorubicin, doxorubicin, etoposide, idarubicin, methotrexate, paclitaxel, vincristine)
• carvedilol
• colchicine
• conivaptan
• cyclosporine
• dabigatran
• deferasirox
• dexamethasone
• digoxin
• dofetilide
• dronedarone
• edoxaban
• enzalutamide
• estrogens (e.g., conjugated estrogen, estradiol, ethinyl estradiol)
• everolimus
• "gliptin" diabetes medications (e.g., linagliptin, saxagliptin, sitagliptin)
• grapefruit juice
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delavirdine, efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• hydrocortisone
• lomitapide
• loperamide
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• mifepristone
• modafinil
• nadolol
• nefazodone
• ondansetron
• paliperidone
• protein kinase inhibitors (e.g., crizotinib, bosutinib dabrafenib, imatinib)
• prucalopride
• quinidine
• quinine
• ranitidine
• rifabutin
• rifampin
• risperidone
• rivaroxaban
• romidepsin
• St. John's wort
• seizure medications (e.g., carbamazepine, phenytoin, phenobarbital)
• silodosin
• siltuximab
• sirolimus
• "statin" anti-cholesterol medications (e.g., atorvastatin, lovastatin, simvastatin)
• tacrolimus
• tocilizumab
• tolvaptan
• warfarin

If you are taking any of these 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.

Medications other than those listed above may interact with this medication. 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.