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CFTR Potentiator — Cystic Fibrosis

Ivacaftor

Brand names: Kalydeco

A CFTR potentiator used in cystic fibrosis for patients with specific gating (and certain other) mutations in the CFTR gene. It is a precision therapy whose suitability depends on the individual's genotype.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

Ivacaftor potentiates the defective CFTR channel at the cell surface, increasing the probability that the gate stays open and enhancing chloride transport to improve mucus hydration and clearance.

Prescribing in practice

  • Confirm an appropriate responsive CFTR mutation before prescribing, as it is ineffective in patients without a suitable genotype.
  • It is metabolised by CYP3A and interacts with strong inducers and inhibitors, so dose adjustment or avoidance may be needed with such co-medication and grapefruit should be avoided.
  • Transaminase elevations can occur, so monitor liver function, and baseline and periodic ophthalmological review is advised in children for lens changes.

Monitoring

Monitor liver enzymes before and during treatment, alongside respiratory function and clinical response, with eye review in paediatric patients.

Counselling the patient

  • Take it with fat-containing food to aid absorption and avoid grapefruit and Seville oranges.
  • Report yellowing of the skin or eyes, abdominal pain or unusual tiredness.

Evidence & guidelines

Ivacaftor is approved for gating-mutation cystic fibrosis and is commissioned in the UK through specialist CF services per NICE arrangements.

Reference: STRIVE Trial (Ramsey et al. NEJM 2011); NICE TA170; SPC Kalydeco; Cystic Fibrosis Trust; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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