Hydroxyzine: risk of QT prolongation and torsade de pointes

Prescribing recommendations for the use of hydroxyzine (Atarax, Ucerax) have been revised following a European review.

Hydroxyzine is an antihistamine used to treat pruritus; it is also used as an anxiolytic. | SCIENCE PHOTO LIBRARY
Hydroxyzine is an antihistamine used to treat pruritus; it is also used as an anxiolytic. | SCIENCE PHOTO LIBRARY

The review examined the safety and efficacy of hydroxyzine, following concerns of heart rhythm abnormalities associated with its use.

The review concluded that hydroxyzine is associated with a small risk of QT interval prolongation and torsade de pointes. Healthcare professionals should avoid prescribing hydroxyzine in elderly patients and in patients who have risk factors for QT prolongation, such as:

  • concomitant use of medicines that prolong the QT interval or that lower heart rate or potassium levels
  • cardiovascular disease
  • family history of sudden cardiac death
  • significant electrolyte imbalance (hypokalaemia or hypomagnesaemia)
  • signigicant bradycardia

Further information
MHRA Drug Safety Update


The lowest effective dose should be prescribed for the shortest possible time, with a maximum daily dose of:

  • 100mg for adults
  • 50mg for the elderly (if use cannot be avoided)
  • 2mg/kg for children (up to 40kg body weight)

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