ivacaftor

ivacaftor

(eye-va-kaf-tor) ,

Kalydeco

(trade name)

Classification

Therapeutic: cystic fibrosis therapy adjuncts
Pharmacologic: temporary class
Pregnancy Category: B

Indications

genetic implication Treatment of cystic fibrosis in patients ≥6 yr with a G551D mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Not effective in patients who are homozygous for the F508del mutation of the CFTR gene.

Action

Acts as a potentiator of the CFTR protein (a chloride channel on the surface of endothelial cells) facilitating chloride transport by increasing the channel-open probability (gating).

Therapeutic effects

Improved lung function with increased weight, decreased exacerbations and CF symptoms.

Pharmacokinetics

Absorption: Some absorption follows oral administration; absorption in enhanced 4–8 fold by fat-containing foods.
Distribution: Unknown.
Protein Binding: >99%.
Metabolism and Excretion: Extensively metabolized, mostly by the CYP3A enzyme system; one metabolite (M1) is pharmacologically active; 87.8% eliminated in feces, negligible urinary elimination.
Half-life: 12 hr.

Time/action profile (blood levels)

ROUTEONSETPEAKDURATION
POwithin 1 wk†4 hr12 hr
†Improved lung function and symptoms.

Contraindications/Precautions

Contraindicated in: Concurrent use of strong CYP3A inducers.
Use Cautiously in: Moderate to severe hepatic impairment (dose ↓ recommended); Concurrent use of CYP3A inhibitors (dose ↓ recommended); Concurrent use of CYP3A and/or P-gp substrates; Severe renal impairment (CCr <30 mL/min) or end stage renal disease; Obstetric: Use in pregnancy only if clearly needed; Lactation: Use cautiously during breast feeding; Pediatric: Children <6 yr (safety not established).

Adverse Reactions/Side Effects

Central nervous system

  • headache (most frequent)
  • dizziness

Ear, Eye, Nose, Throat

  • nasal congestion (most frequent)
  • oropharyngeal pain

Gastrointestinal

  • nausea (most frequent)
  • abdominal pain
  • diarrhea
  • ↑ liver enzymes

Dermatologic

  • rash (most frequent)

Musculoskeletal

  • arthralgia
  • musculoskeletal chest pain
  • mylagia

Endocrinologic

  • hyperglycemia
  • hypoglycemia

Interactions

Drug-Drug interaction

Strong CYP3A inducers including rifampin, rifabutin, phenobarbital, carbamazepine and phenytoin ↓ levels and effectiveness; avoid concurrent useStrong CYP3A inhibitors including ketoconazole, itraconazole, posaconazole, voriconazole, telithromycin, and clarithromycin may ↑ levels and risk of adverse reactions (dosage ↓ recommended). Moderate CYP3A inhibitors including fluconazole or erythromycin may ↑ levels and risk of adverse reactions (dosage ↓ recommended).May ↑ levels and effects of CYP3A substrates including alprazolam, diazepam, midazolam and triazolam.May ↑ levels and effects of P-gp substrates including digoxin, cyclosporine and tacrolimus.May alter the effects of warfarin.St. John's wort may ↓ levels and effectiveness; avoid concurrent use.Grapefruit or Seville oranges may ↑ levels and ↑ risk of toxicity; avoid concurrent use.

Route/Dosage

Oral (Adults and Children ≥6 yr) 150 mg q 12 hr with fat-containing food; Concurrent strong CYP3A inhibitors—150 mg twice weekly; cConcurrent moderate CYP3A inhibitors—150 mg once daily.

Hepatic Impairment

Oral (Adults and Children ≥6 yr) Moderate hepatic impairment—150 mg once daily; Severe hepatic impairment—150 mg once daily or less.

Availability

Tablets: 150 mg

Nursing implications

Nursing assessment

  • Monitor lung function (FEV, lung sounds) before and periodically during therapy.
  • Lab Test Considerations: May cause ↑ serum transaminases. Monitor AST and ALT before, every 3 months for the first year, and annually thereafter. If AST or ALT >5 times the upper limit of normal, interrupt therapy. Once AST or ALT have returned to normal, consider the benefits and risks before resuming therapy.

Potential Nursing Diagnoses

Deficient knowledge, related to disease process and medication regimen (Patient/Family Teaching)

Implementation

  • Oral: Administer with fat-containing food.

Patient/Family Teaching

  • Instruct patient to take as directed with a fat-containing meal to increase absorption. Fat-containing foods include eggs, butter, peanut better, cheese pizza.
  • Advise patient to avoid eating grapefruit or seville oranges or drinking grapefruit juice during therapy.
  • Advise patient to notify health care professional if symptoms of liver problems (pain or discomfort in right abdominal area, yellowing of skin or whites of eyes, loss of appetite, nausea, vomiting, dark amber-colored urine) occur.
  • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
  • Advise female patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
  • Emphasize the importance of blood tests to monitor liver function.

Evaluation/Desired Outcomes

  • Improved lung function with increased weight, decreased exacerbations and symptoms in patients with cystic fibrosis.
References in periodicals archive ?
M2 PHARMA-August 22, 2019-Vertex Pharmaceuticals files US FDA new drug application for VX-445 tezacaftor and ivacaftor triple combination regimen
M2 EQUITYBITES-August 22, 2019-Vertex Pharmaceuticals files US FDA new drug application for VX-445 tezacaftor and ivacaftor triple combination regimen
ENPNewswire-August 21, 2019--Vertex Pharmaceuticals - FDA Accepts New Drug Application for VX-445, Tezacaftor and Ivacaftor Combination Treatment
Vertex announced the FDA accepted its new drug application, or NDA, for the VX-445, tezacaftor and ivacaftor triple combination regimen.
Food and Drug Administration (FDA) for the triple combination of VX-445 (elexacaftor), tezacaftor and ivacaftor. A Marketing Authorization Application (MAA) submission to the European Medicines Agency(EMA) is planned for the fourth quarter of 2019.
FRIDAY, July 19, 2019 (HealthDay News) -- For patients with cystic fibrosis (CF), ivacaftor use is associated with a reduction in pathogens, including Pseudomonas aeruginosa, according to a study published online July 19 in the Annals of the American Thoracic Society.
Dosage in children ages 6 to 12 years weighing less than 30 kg is one tablet of 50 mg tezacaftor and 75 mg ivacaftor in the morning and one tablet of 75 mg ivacaftor approximately 12 hours later.
Symdeko (tezacaftor + ivacaftor), which have MWs of about 521 and 392, is indicated for the treatment of patients with cystic fibrosis who are homozygous for the F508del mutation or who have at least one mutation in the cystic fibrosis trans-membrane conductance regulator gene.
Clinical review report: ivacaftor (Kalydeco) for the treatment of cystic fibrosis in patients 18 years of age and older with a R117H mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene [Internet].
Vertex Pharmaceuticals' Ivacaftor is the first originator small molecule drug for the treatment of protein malfunctioning caused by the genetic defect in cystic fibrosis patients.
Ivacaftor, indicated for people who carry the G551D mutation (<5% of all people with CF), has shown the best clinical results.