Hydroxyzine (Atarax, Ucerax): risk of QT interval prolongation and Torsade de Pointes

The maximum adult daily dose of hydroxyzine is now 100 mg. Do not prescribe hydroxyzine to people with a prolonged QT interval or risk factors for QT interval prolongation.

When using hydroxyzine:

  • do not prescribe hydroxyzine to people with a prolonged QT interval or who have risk factors for QT interval prolongation (see below)
  • avoid use in the elderly - they are more susceptible than younger patients to the side effects of hydroxyzine
  • consider the risks of QT interval prolongation and Torsade de Pointes before prescribing to patients taking medicines that lower heart rate or potassium levels
  • the maximum daily dose is now
    • 100 mg for adults
    • 50 mg for the elderly (if use cannot be avoided)
    • 2 mg per kg body weight for children up to 40 kg in weight
  • prescribe the lowest effective dose for as short a time as possible
  • continue to report any suspected side effects to hydroxyzine or any other medicine on a Yellow Card

Hydroxyzine is an antihistamine used to treat pruritus in adults and children and anxiety in adults.

A European review of the safety and efficacy of hydroxyzine has been undertaken following concerns of heart rhythm abnormalities associated with this medicine. The review concluded that hydroxyzine is associated with a small risk of QT interval prolongation and Torsade de Pointes. Such events are most likely to occur in patients who already have risk factors for QT prolongation, such as:

  • concomitant use of medicines that prolong the QT interval
  • cardiovascular disease
  • family history of sudden cardiac death
  • significant electrolyte imbalance (low potassium or magnesium levels)
  • significant bradycardia

Further information

Letter sent to healthcare professionals in April 2015

European Medicines Agency announcement March 2015

Article citation: Drug Safety Update volume 8 issue 9 April 2015: 1

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