Hydroxyzine is a potent antihistamine used to treat N/V and as an adjunctive therapy for perioperative sedation. It has also been demonstrated to show effective anxiolytic effects as compared to benzodiazepines. Common side effects are headache, dry mouth, and over-sedation. Serious reactions that can occur include respiratory depression and QT-interval prolongation.

Key Points

  • Hydroxyzine [hye DROX ee zeen] (Vistaril)
    • Mechanism of Action
      • Blocks H1 histamine receptors
        • Potent inverse agonist which suppresses signalling at receptor
    • Clinical Use
      • Sedation 
        • Used to induce sedation around surgical operations
      • Antiemetic
        • Treats N/V associated with motion sickness or other medications
      • Anxiolytic 
    • Side Effects and Adverse Reactions 
      • Anticholinergic effects (delirium, dry mouth, sedation, blurred vision)
      • Respiratory depression
        • Avoid in patients with asthma or COPD
      • QT-interval prolongation
        • Avoid in patients with existing QT-interval prolongation