What is the proper dosage of hydroxyzine (antihistamine) for a woman with anxiety and insomnia?

Hydroxyzine Dosage for Anxiety and Insomnia

For a 5'7" woman weighing 140 lbs with anxiety and insomnia, the appropriate hydroxyzine dosage is 25 mg three times daily for anxiety with an additional 50 mg at bedtime for insomnia. 1

Dosing Guidelines

• According to the FDA label, the recommended dosage for anxiety in adults is 50-100 mg divided throughout the day (typically 25 mg three to four times daily) 1
• For sedative effects and insomnia management, the recommended dosage is 50-100 mg at bedtime 1
• For a woman of average weight (140 lbs), starting with the lower end of the dosage range is appropriate to minimize side effects while maintaining efficacy 1

Dosing Algorithm

1. For daytime anxiety management:

   • Start with 25 mg three times daily 1
   • May increase to 25 mg four times daily if needed after 3-5 days of treatment 1, 2

2. For insomnia:

   • Add 50 mg at bedtime 1, 3
   • Take 30-60 minutes before desired sleep time 4

Efficacy Evidence

• Hydroxyzine has demonstrated efficacy for generalized anxiety disorder at doses of 50 mg/day, with significant improvement compared to placebo starting from the first week of treatment 4, 5
• The anxiolytic effects persist throughout treatment and even after discontinuation without rebound anxiety 4, 3
• Studies show hydroxyzine is comparable in efficacy to benzodiazepines and buspirone for anxiety management 2, 5

Side Effect Profile

• The most common side effect is transient sleepiness/drowsiness (28% vs 14% with placebo), which typically appears during the first week and progressively diminishes 4
• Other reported side effects include dry mouth (14%), weight gain (12%), and loss of concentration (9%) 4
• Hydroxyzine has a more favorable safety profile than benzodiazepines, with no risk of dependency or withdrawal symptoms 3

Important Considerations

• Dosage should be adjusted based on the patient's response to therapy 1
• The sedating properties make hydroxyzine particularly useful for patients with anxiety-induced insomnia 6
• Caution should be exercised when combining hydroxyzine with other medications that have alpha-adrenergic antagonism activity (like certain antipsychotics) due to potential adverse effects 6
• Unlike benzodiazepines, hydroxyzine does not cause tolerance, addiction, or withdrawal symptoms upon discontinuation 4, 3

Monitoring

• Assess for excessive daytime sedation during the first week of treatment 4
• Evaluate efficacy for both anxiety and insomnia symptoms after 1-2 weeks 4, 5
• If inadequate response after 2 weeks, consider increasing the dose within the recommended range 1