Hydroxyzine (Vistaril) Dosing Guidelines
The recommended dosing for hydroxyzine (Vistaril) varies by indication, with adults typically receiving 25-100 mg 3-4 times daily depending on the condition being treated. 1
Adult Dosing by Indication
Anxiety and Tension
- Initial dose: 50-100 mg four times daily
- Maximum daily dose: 400 mg divided throughout the day
Pruritus (Allergic Conditions)
- Standard dose: 25 mg three to four times daily
- Maximum daily dose: 100 mg divided throughout the day
Preoperative Sedation
- Single dose: 50-100 mg
Pediatric Dosing
Children under 6 years
- 50 mg total daily dose, divided throughout the day
Children over 6 years
- 50-100 mg total daily dose, divided throughout the day
Administration Considerations
- Hydroxyzine can be taken with or without food
- When sedation is desired, doses can be timed for bedtime administration
- For daytime anxiety control, lower doses may be preferred to minimize sedation
Important Precautions
Sedation and CNS Effects
- Hydroxyzine causes significant sedation in up to 28% of patients (vs 14% with placebo) 2
- Sedation typically appears during the first week of treatment and may diminish over time 2
- Can impair driving ability and increase risk of accidents 3
- Avoid concomitant use with alcohol or other CNS depressants
Special Populations
- Elderly patients: Use lower doses due to increased sensitivity to CNS effects 4
- Renal impairment: Reduce dose by 50% in moderate impairment; avoid in severe impairment 5
- Hepatic impairment: Use with caution or avoid in severe liver disease 5
- Pregnancy: Contraindicated, especially during first trimester 5
Other Side Effects
- Dry mouth (14% vs 5% with placebo) 2
- Weight gain (12% vs 10% with placebo) 2
- Concentration difficulties (9% vs 8% with placebo) 2
- Insomnia (9% vs 6% with placebo) 2
Comparative Efficacy
- Hydroxyzine has demonstrated superior efficacy to placebo for generalized anxiety disorder, with benefits appearing within the first week of treatment 6, 2
- Unlike benzodiazepines, hydroxyzine does not cause dependency or withdrawal symptoms upon discontinuation 6, 2
- Can be used as an alternative to benzodiazepines when dependency is a concern
Clinical Pearls
- Hydroxyzine can be safely combined with SSRIs for patients with comorbid depression and anxiety, unlike benzodiazepines which may interfere with SSRI efficacy 7
- For patients requiring 24-hour symptom control of allergic conditions, consider non-sedating antihistamines during the day and hydroxyzine at night 5
- Dosage should be adjusted according to individual patient response 1
- Monitor for excessive sedation, especially when initiating therapy