Formulary
Ivacaftor: Indications, Dosing, Side Effects and Interactions
Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) protein potentiator that increases chloride transport in the abnormal CFTR protein.
MedNext Academy | 3 min read
Ivacaftor: Indications, Dosing, Side Effects and Interactions
Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) protein potentiator that increases chloride transport in the abnormal CFTR protein.
Drug action
Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) protein potentiator that increases chloride transport in the abnormal CFTR protein.
Indications and dose
**Cystic fibrosis (specialist use only)**
- **Adult** (By Mouth Using Tablets): 150 mg every 12 hours.
**Cystic fibrosis (specialist use only) for ivacaftor**
- **Child 6-17 years (body-weight 25 kg and above)** (By mouth using tablets): 150 mg every 12 hours.
Cautions
Organ transplantation (no information available)
Side effects
Common or very common Breast abnormalities; diarrhoea; dizziness; ear discomfort; flatulence; gastrointestinal discomfort; headache; hypoglycaemia; increased risk of infection; nasal complaints; nausea; oropharyngeal pain; ototoxicity; respiratory disorders; skin reactions; throat erythema; tympanic membrane hyperaemia Uncommon Gynaecomastia Frequency not known Hepatic disorders Side-effects, further information Manufacturer advises interrupt treatment if transaminase levels more than 5 times the upper limit of normal or transaminase levels more than 3 times the upper limit of normal and blood bilirubin more than twice the upper limit of normal-consult product literature.
Interactions
**Severe interactions:**
- Coadministration of IVA with rifampicin, a strong CYP3A inducer, significantly decreased IVA area under the curve (AUC) by 89%.
**Other interactions (16):**
- Examples of strong CYP3A inducers include: rifampicin, rifabutin, phenobarbital, carbamazepine, phenytoin, and St.
- John's wort ( Hypericum perforatum ) CYP3A inhibitors Coadministration with itraconazole, a strong CYP3A inhibitor, increased ELX AUC by 2.8fold and TEZ AUC by 4.0 to 4.5fold.
- When coadministered with itraconazole and ketoconazole, IVA AUC increased by 15.6fold and 8.5fold, respectively.
- Examples of strong CYP3A inhibitors include: ketoconazole, itraconazole, posaconazole, and voriconazole telithromycin and clarithromycin Simulations indicated that coadministration with...
- Coadministration of fluconazole increased IVA AUC by 2.9fold.
- Examples of moderate CYP3A inhibitors include: fluconazole erythromycin Coadministration with grapefruit juice, which contains one or more components that moderately inhibit CYP3A, may increase...
Pregnancy
Manufacturer advises avoid-limited information available.
Breast feeding
Manufacturer advises avoid-present in milk in animal studies.
Hepatic impairment
Avoid unless benefit outweighs risk in severe impairment (risk of increased exposure-serious liver injury reported). M Dose adjustments For tablets, reduce dose to 150 mg once daily in moderate impairment; in severe impairment reduce starting dose to 150 mg on alternate days or less frequently, adjust dosing interval according to clinical response and tolerability. The evening dose of ivacaftor should not be taken. M
Renal impairment
Manufacturer advises caution in severe impairment or end-stage renal disease-limited information available.
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
Inside MedNext for this topic
- 411 MedNext-authored chapters
- 80,000+ MCQ bank
- 15 study modes
- Growing visual cheat sheets
Study modes
- Notes
- MCQ
- Audio
- Video
- Visual
- 3D Anatomy
- Trace
- Flashcards
- Mnemonics
- Image Bank
- Clinical
- Microscopy
- Audio QBank
- Cadaver
- Book Match
Continue reading
Subject HubPharmacology Hub
All pharmacology resources in one place.
Drug SchedulesIndian Drug Schedules
Schedule H, H1, X and G classifications.
FormularyBrowse all drugs
Search 1,850+ drug profiles.
Study Ivacaftor in the MedNext app
Challenge yourself with targeted pharmacology MCQs on this drug class. Every explanation links back to the chapter that teaches the concept.
Start drug challengeExplore the full formulary

