Hydroxyzine Dosing for Anxiety
For adults with generalized anxiety disorder, the FDA-approved dose of hydroxyzine (Vistaril) is 50-100 mg four times daily, though benzodiazepines like lorazepam represent a more evidence-based first-line approach according to current clinical guidelines. 1
FDA-Approved Dosing
Adult dosing for anxiety and tension:
- 50-100 mg four times daily (QID) 1
- Dosage should be adjusted according to the patient's response to therapy 1
Pediatric dosing:
- Children under 6 years: 50 mg daily in divided doses 1
- Children over 6 years: 50-100 mg daily in divided doses 1
Critical Clinical Considerations
Hydroxyzine should not be considered first-line therapy when benzodiazepines are appropriate and not contraindicated. 2 The National Institute for Health and Care Excellence (NICE) recommends benzodiazepines such as lorazepam 0.5-1 mg orally up to four times daily as needed for acute anxiety management, representing stronger guideline support than hydroxyzine 2.
Important Timing Issue
- Optimal assessment of hydroxyzine response requires 1 week of scheduled dosing, making titration challenging when used PRN 2
- Clinical trials show significant anxiety reduction begins during the first week of treatment 3, 4
Efficacy Evidence
While hydroxyzine demonstrates superiority over placebo in controlled trials:
- Statistically significant anxiolytic effect at 50 mg/day starting in the first week 3
- Efficacy maintained throughout 4 weeks without rebound anxiety upon discontinuation 3
- Equivalent efficacy to benzodiazepines and buspirone in head-to-head comparisons 5
However, a 2010 Cochrane review concluded that due to high risk of bias in included studies, small sample sizes, and limited number of trials, hydroxyzine cannot be recommended as a reliable first-line treatment for GAD. 5
Common Adverse Effects
Most frequent side effect is transient sleepiness:
- Occurs in 28% of patients (vs 14% with placebo) 3
- Typically appears during the first week and progressively diminishes 3
- Can significantly impair driving and psychomotor function 6
Other reported effects:
- Dry mouth (14% vs 5% placebo) 3
- Weight gain (12% vs 10% placebo) 3
- Loss of concentration (9% vs 8% placebo) 3
Key Clinical Pitfalls
Driving impairment: Hydroxyzine produces CNS depressant effects including fatigue, sedation, and impaired memory/concentration 6. Patients should be warned about driving risks, particularly during the first week of treatment.
Polypharmacy concerns: In real-world DUID investigations, hydroxyzine was rarely found alone—common combinations included antidepressants (74%), opioids (44%), and anticonvulsants (38%) 6. Exercise caution with concurrent CNS depressants.
Lack of dependency: Unlike benzodiazepines, hydroxyzine shows no evidence of organ toxicity or dependency 4, which may be advantageous in patients with substance use concerns.