ivacaftor + tezacaftor at a glance
Medicine class
CFTR corrector and potentiator combination.
Who it is for
People aged 6 years and over with an eligible CFTR genotype confirmed by validated testing.
Taking the tablets
Take with fat-containing food and swallow whole; do not chew, crush or break them.
Food to avoid
Avoid grapefruit and products containing grapefruit.
Key monitoring
Liver blood tests are needed before and during treatment; children also need eye examinations.
What is ivacaftor + tezacaftor used for?
Licensed with separate ivacaftor tablets for cystic fibrosis in people aged 6 years and over with an eligible genotype.
Homozygous F508del CFTR mutation.
Heterozygous F508del with one of these CFTR mutations: P67L, R117C, L206W, R352Q, A455E, D579G, 711+3A→G, S945L, S977F, R1070W, D1152H, 2789+5G→A, 3272-26A→G or 3849+10kbC→T.
How does ivacaftor + tezacaftor work?
Tezacaftor helps more CFTR protein reach the cell surface. Ivacaftor helps the protein channels stay open, improving chloride movement and airway-surface hydration.
ivacaftor + tezacaftor preparations and strengths
Tablet
Route: Oral
Strengths: 50 mg + 75 mg, 100 mg + 150 mg
How to take ivacaftor + tezacaftor
Follow the specialist cystic fibrosis team's plan. The combination tablet is used with a separate ivacaftor tablet.
Take each tablet with food containing fat.
Swallow tablets whole; do not chew, crush or break them.
Avoid grapefruit-containing food and drink.
Continue other cystic fibrosis treatments unless the specialist team advises otherwise.
ivacaftor + tezacaftor side effects
Common or expected effects
- Headache or dizziness
- Cold-like symptoms, blocked nose or sore throat
- Abdominal pain, diarrhoea or nausea
- Rash
- Raised liver enzymes on blood testing
- Ear discomfort, tinnitus or balance symptoms
Get urgent medical advice
- Possible liver injury: jaundice, dark urine, upper-right abdominal pain, loss of appetite, nausea or vomiting requiring prompt assessment
ivacaftor + tezacaftor in pregnancy
Evidence in pregnancy is limited. Product information advises precautionary avoidance, while current UK pregnancy information reports no indication of fetal harm and notes that maintaining cystic fibrosis control may justify continuation. Discuss planning, stopping or changing treatment with the cystic fibrosis and obstetric teams.
ivacaftor + tezacaftor while breastfeeding
It is unknown whether tezacaftor, ivacaftor or their metabolites enter human milk, and risk to an infant cannot be excluded. The specialist team should weigh the benefits of breastfeeding against those of continued treatment.
ivacaftor + tezacaftor interactions
Check prescribed, over-the-counter and herbal products with the cystic fibrosis team or pharmacist.
Rifampicin, rifabutin, carbamazepine, phenytoin, phenobarbital and St John’s wort
Strong CYP3A induction can substantially reduce exposure and effectiveness, so combined use is not recommended.
Azole antifungals, clarithromycin and telithromycin
Strong CYP3A inhibition can markedly increase exposure, requiring specialist review.
Fluconazole, erythromycin and verapamil
Moderate CYP3A inhibition increases exposure and requires specialist review.
Common questions about ivacaftor + tezacaftor
Answers are fully visible for fast scanning and source review.
What is ivacaftor + tezacaftor used for?
It treats cystic fibrosis in people aged 6 years or older whose CFTR genotype matches the licensed mutations.
Does it cure cystic fibrosis?
No. It improves the function of certain abnormal CFTR proteins but does not remove the inherited gene change.
Why is separate ivacaftor used?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.