Hydroxyzine (Vistaril/Atarax): Uses, Dosage, Side Effects, and What to Expect

Hydroxyzine (brand name: Vistaril (pamoate), Atarax (hydrochloride)) is a first-generation antihistamine / anxiolytic. Hydroxyzine is a first-generation antihistamine that crosses the blood-brain barrier. It blocks histamine H1 receptors (causing sedation), muscarinic acetylcholine receptors (anticholinergic effects), and serotonin 5-HT2A receptors (anxiolytic effects). Unlike benzodiazepines, it does not act on GABA receptors and carries no risk of dependence or withdrawal seizures, making it a safer choice for patients with substance use history.

• Anxiety (short-term)
• Pruritus (itching)
• Preoperative sedation

Common off-label uses:

• Insomnia
• Generalized Anxiety Disorder (adjunctive)
• Panic attacks (acute)
• Alcohol withdrawal (adjunctive)
• Nausea

Anxiety: 50-100 mg up to four times daily, or 50-100 mg as needed. Insomnia: 25-100 mg at bedtime. Start lower in elderly (25 mg). Available as capsules (pamoate), tablets (hydrochloride), oral solution, and injection.

Anxiolytic and sedative effects begin within 15-30 minutes of oral administration. Peak effect at 2 hours. Duration 4-6 hours.

• Drowsiness (most common)
• Dry mouth
• Dizziness
• Headache
• Constipation
• Blurred vision

• QT prolongation (particularly at higher doses or in patients with cardiac risk factors)
• Anticholinergic toxicity in overdose or elderly
• Paradoxical agitation (rare)

Additive sedation with alcohol, benzodiazepines, opioids, and other CNS depressants. Additive anticholinergic effects with other anticholinergic drugs. Caution with QT-prolonging medications.

Contraindicated in early pregnancy. Generally avoided throughout pregnancy due to limited safety data.

No physiological dependence or withdrawal syndrome. Can be stopped abruptly without tapering.