Ivacaftor Dosage

Usual Adult Dose for Cystic Fibrosis

150 mg orally every 12 hours

Uses:
-For the treatment of cystic fibrosis (CF) in patients six years and older with one of the following mutations in the CFTR gene: G551D, G1244E, G1349D, G178R, G551S, S1251N, S1255P, S549N, or S549R
-For the treatment of CF in patients age 6 years and older who have an R117H mutation in the CFTR gene

Comments:
-This drug should be taken with fat-containing food.

Usual Pediatric Dose for Cystic Fibrosis

6 years and older:
150 mg orally every 12 hours

Uses:
-For the treatment of cystic fibrosis (CF) in patients six years and older with one of the following mutations in the CFTR gene: G551D, G1244E, G1349D, G178R, G551S, S1251N, S1255P, S549N, or S549R
-For the treatment of CF in patients age 6 years and older who have an R117H mutation in the CFTR gene

Comments:
-This drug should be taken with fat-containing food.

Renal Dose Adjustments

Mild to moderate renal dysfunction: No adjustment recommended
Severe renal dysfunction (CrCl 30 mL/min or less) or end-stage renal disease: Caution is recommended

Liver Dose Adjustments

Mild liver dysfunction (Child-Pugh A): No adjustment recommended
Moderate liver dysfunction (Child-Pugh B): 150 mg orally once a day
Severe liver dysfunction (Child-Pugh C): 150 mg orally once a day or less frequently; caution is recommended

Dose Adjustments

When coadministered with moderate CYP450 3A inhibitors (e.g., fluconazole): 150 mg orally once a day
When coadministered with strong CYP450 3A inhibitors (e.g., ketoconazole, itraconazole, posaconazole, voriconazole, telithromycin, clarithromycin): 150 mg orally twice a week
When coadministered with strong CYP450 3A inducers (e.g., rifampin, St. John's Wort): Not recommended

Precautions

-Safety and efficacy have not been established in patients younger than 6 years.
-Safety and efficacy have not been established in patients age 65 years or older.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:
-Tablets should be swallowed whole, not crushed, chewed, dissolved, or divided.
-This drug should be given with fat-containing food (e.g., eggs, butter, peanut butter, cheese pizza, etc.).
-Food containing grapefruit or Seville oranges should be avoided during ivacaftor therapy.

General:
-This drug should only be prescribed by physicians with experience in the treatment of cystic fibrosis.
-If patient genotype is unknown, an FDA-cleared CF mutation test should be used to detect the presence of a CFTR mutation followed by verification with bidirectional sequencing when recommended by the mutation test instructions for use.
-This drug is not effective in CF patients who are homozygous for the F508del mutation in the CFTR gene.
-This drug has not been studied in patients with CF who have undergone organ transplantation. Therefore, use in transplanted patients is not recommended.

Monitoring:
Hepatic: Liver function tests (prior to starting treatment, every 3 months during the first year of treatment, and yearly thereafter).

Patient advice:
-This drug should be taken with a fat-containing meal or snack.
-Dizziness has been reported with ivacaftor therapy. If dizziness occurs, do not drive or operate machinery until symptoms abate.