The nurse is teaching an adult with cystic fibrosis who is starting ivacaftor. Which statement shows correct understanding?
1I will take each dose on an empty stomach and avoid foods containing fat because they reduce absorption.
2I can stop airway-clearance therapy once ivacaftor begins because the drug immediately clears lung secretions.
3I will take each dose about 12 hours apart with fat-containing food and avoid grapefruit products.✓ Correct answer
4If I remember a missed dose more than 6 hours late, I will take two doses together with my next meal.
Explanation
For adults, ivacaftor is taken every 12 hours with fat-containing food to improve absorption. Grapefruit products can increase ivacaftor exposure through CYP3A inhibition and should be avoided. A dose remembered more than 6 hours late is skipped rather than doubled. Ivacaftor does not replace prescribed airway-clearance therapy.
Clinical reasoning Ivacaftor is a CFTR potentiator whose exposure increases with fat-containing food. Grapefruit inhibits CYP3A and can raise the drug concentration.
Decision rule Pair each prescribed dose with fat-containing food, keep the doses about 12 hours apart, avoid grapefruit, and never double a late dose. Continue the rest of the cystic-fibrosis plan unless the prescriber changes it.
Scenario 16-year-old with cystic fibrosis (heterozygous F508del) starting elexacaftor/tezacaftor/ivacaftor (Trikafta) AM dose and ivacaftor PM dose. Outpatient teaching.
CFTR modulator — Drugs correcting CFTR protein function in cystic fibrosis; ivacaftor, tezacaftor, elexacaftor, lumacaftor.
Fat-containing food — Required for lipophilic drug absorption; standard counseling for CFTR modulators.