Physicians should take certain precautions in prescribing the first-generation antihistamine hydroxyzine to minimize the drug’s risk for potentially fatal heart arrhythmias, the European Medicines Agency (EMA) announced recently.
Hydroxyzine (Atarax, Vistaril) is approved in the European Union (EU) for treating anxiety disorders, sleep disorders, and pruritus as well as premedicating patients before surgery, with the indications varying by individual EU nation. Similar indications are approved in the United States. It is also used off label as an antiemetic/antinausea agent in the United States for adults.
The EMA’s Pharmacovigilance Risk Assessment Committee (PRAC) reviewed the safety of hydroxyzine at the request of Hungarian drug regulators, who were worried about adverse cardiac effects. PRAC confirmed a small but definite risk for QT interval prolongation and torsades de pointes, which can trigger ventricular fibrillation. However, the committee determined that clinicians could continue to prescribe the drug under the following conditions:
- Prescribe hydroxyzine at the lowest effective dose for the shortest time possible.
- Hydroxyzine must not be used by patients with known risk factors for heart arrhythmias or who are taking drugs that increase the risk for QT prolongation.
- The maximum daily dose should not exceed 100 mg in adults and 2 mg per kg of body weight in children weighing up to 40 kg.
- Hydroxyzine is not recommended for the elderly, but if clinicians believe that its use is unavoidable, the maximum daily dose for this age group should be 50 mg.
PRAC also recommended the continued monitoring of hydroxyzine to ensure that these precautions protect the public.
The committee’s recommendations now go to another EU regulatory body, the Co-ordination Group for Mutual Recognition and Decentralised Procedures-Human, for further action. This agency represents individual EU member states, each of which approves drugs for marketing within its borders.