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Ivacaftor / tezacaftor Side Effects

Medically reviewed by Drugs.com. Last updated on Jun 30, 2021.

For the Consumer

Applies to ivacaftor / tezacaftor: oral tablet

Side effects requiring immediate medical attention

Along with its needed effects, ivacaftor / tezacaftor may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking ivacaftor / tezacaftor:

Rare

Incidence not known

  • Blindness
  • blurred vision
  • dark urine
  • decreased vision
  • light-colored stools
  • loss of appetite
  • yellow skin or eyes

Side effects not requiring immediate medical attention

Some side effects of ivacaftor / tezacaftor may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

For Healthcare Professionals

Applies to ivacaftor / tezacaftor: oral tablet

General

The most commonly reported side effects have included headache, nasopharyngitis, nausea, sinus congestion, and dizziness.[Ref]

Nervous system

Very common (10% or more): Headache (14%)

Common (1% to 10%): Dizziness

Ocular

Frequency not reported: Non-congenital lens opacities

Respiratory

Common (1% to 10%): Sinus congestion

Gastrointestinal

Common (1% to 10%): Nausea

Uncommon (0.1% to 1%): Distal intestinal obstruction syndrome

Hepatic

Common (1% to 10%): Transaminase elevations

The incidence of maximum transaminase (ALT or AST) elevations to greater than 8 times the upper limit of normal (8 x ULN), greater than 5 x ULN, or greater than 3 x ULN was similar between drug treated and placebo treated patients (0.2%, 1%, 3.4% versus 0.4%, 1%, 3.4%, respectively). A total of 3 patients in clinical trials permanently discontinued therapy due to elevated transaminases (1 drug treated and 2 on placebo). No drug-treated patient experienced a transaminase elevation greater than 3 x ULN associated with elevated total bilirubin greater than 2 x ULN.

Frequently asked questions

References

1. "Product Information. Symdeko 4-Week (ivacaftor-tezacaftor)." Vertex Pharmaceuticals, Cambridge, MA.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.