Overview
Hydroxyzine is a first-generation antihistamine with sedative, anxiolytic, antiemetic, and anticholinergic properties. It is commonly used for anxiety, pruritus, and as a preoperative sedative.
Mechanism of Action
Acts as a histamine H1 receptor antagonist and also exhibits anticholinergic, anxiolytic, and sedative effects through central nervous system depression.
Indications
- Anxiety and tension
- Pruritus due to allergic conditions
- Preoperative sedation
- Nausea and vomiting
Dosage
Adults: 25-100 mg orally 3-4 times daily. Children >6 years: 50-100 mg/day in divided doses. Adjust based on indication and patient response.
Contraindications
- Hypersensitivity to hydroxyzine or components
- Early pregnancy
- Breastfeeding
- Patients with prolonged QT interval
Side Effects
- Drowsiness
- Dry mouth
- Headache
- Dizziness
- Blurred vision
- Constipation
- Tachycardia
Interactions
- CNS depressants (alcohol, opioids, benzodiazepines)
- Anticholinergic drugs
- QT-prolonging agents
- Monoamine oxidase inhibitors (MAOIs)