What is the recommended dosage and usage of hydroxyzine for anxiety and insomnia?

Hydroxyzine for Anxiety and Insomnia

For anxiety, hydroxyzine 50-100 mg four times daily is FDA-approved and effective, while for insomnia, hydroxyzine is not recommended as first-line therapy—instead, use FDA-approved alternatives like eszopiclone, zolpidem, or zaleplon. 1, 2

FDA-Approved Dosing for Anxiety

Hydroxyzine is FDA-approved for symptomatic relief of anxiety and tension associated with psychoneurosis at 50-100 mg four times daily in adults. 1

• For children under 6 years: 50 mg daily in divided doses 1
• For children over 6 years: 50-100 mg daily in divided doses 1
• As premedication sedation: 50-100 mg for adults, 0.6 mg/kg for children 1

Evidence for Anxiety Treatment

Hydroxyzine demonstrates statistically significant anxiolytic effects beginning in the first week of treatment, with particular efficacy for the cognitive component of anxiety. 3, 4

• A controlled trial showed hydroxyzine 50 mg daily was superior to placebo on all anxiety measures from week one through week four 4
• Efficacy persisted after abrupt discontinuation without rebound anxiety or withdrawal symptoms 4
• Compared to benzodiazepines (chlordiazepoxide) and buspirone, hydroxyzine showed equivalent efficacy 3
• Hydroxyzine demonstrated greater and more rapid cognitive improvement compared to lorazepam in controlled trials 5

Position in Insomnia Treatment

The American Academy of Sleep Medicine explicitly recommends against using antihistamines like hydroxyzine for insomnia treatment, citing limited efficacy evidence. 2

• Diphenhydramine (50 mg), a similar antihistamine, received a negative recommendation for both sleep onset and maintenance insomnia 2
• Over-the-counter antihistamines have "very limited" evidence for efficacy and safety, with potential for serious anticholinergic side effects 2
• Long-term use of non-prescription antihistamine treatments is not recommended due to unknown safety and efficacy 2

Preferred Alternatives for Insomnia

If insomnia treatment is needed, the American Academy of Sleep Medicine recommends FDA-approved agents with established efficacy:

For Sleep Onset Insomnia:

• Zaleplon 10 mg 2
• Zolpidem 10 mg 2
• Ramelteon 8 mg (non-scheduled, no abuse potential) 2, 6
• Triazolam 0.25 mg 2

For Sleep Maintenance Insomnia:

• Eszopiclone 2-3 mg 2, 6
• Doxepin 3-6 mg 2, 6
• Suvorexant 10-20 mg 2, 6
• Temazepam 15 mg (7.5 mg in elderly) 2, 6

Tolerability Profile

The most common side effect is transient sleepiness (28% vs 14% placebo), which typically appears during the first week and progressively diminishes. 4

• Other side effects include: dry mouth (14%), weight gain (12%), loss of concentration (9%), insomnia (9%) 4
• Hydroxyzine causes more sleepiness/drowsiness than benzodiazepines and buspirone 3
• Unlike benzodiazepines, hydroxyzine shows no evidence of dependency or organ toxicity 5
• Critical warning: Hydroxyzine has alpha-adrenergic antagonism activity and can increase priapism risk when combined with antipsychotics like risperidone 7

Clinical Decision Algorithm

For anxiety symptoms:

1. Start hydroxyzine 50 mg four times daily (FDA-approved dose) 1
2. Adjust dose to 100 mg four times daily if needed for symptom control 1
3. Expect therapeutic effect within the first week 4
4. Monitor for transient daytime sleepiness in week one 4

For insomnia symptoms:

1. Do not use hydroxyzine as first-line therapy 2
2. Choose based on insomnia type: zaleplon/ramelteon for onset problems, eszopiclone/doxepin/suvorexant for maintenance problems 2, 6
3. Consider shorter half-life agents for sleep onset, longer-acting for maintenance 6
4. Reduce doses in elderly patients and those with hepatic impairment 6

Important Caveats

• Hydroxyzine can be used as adjunctive support during benzodiazepine withdrawal at 25-50 mg daily, reducing withdrawal symptoms and anxiety 8
• The Cochrane review concluded that despite superiority over placebo, high risk of bias in studies prevents recommending hydroxyzine as reliable first-line GAD treatment 3
• Buspirone (5 mg twice daily, maximum 60 mg daily) is an alternative non-sedating anxiolytic, though it requires 2-4 weeks to become effective 2, 6
• Avoid combining hydroxyzine with antipsychotics due to increased risk of priapism and additive sedation 7