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

Hydroxyzine Dosage and Usage for Anxiety and Itching

For anxiety, hydroxyzine is recommended at 25-50 mg QID (four times daily) for adults, while for itching/pruritus, the recommended dosage is 10-25 mg QID or at bedtime. 1, 2

Dosage Recommendations by Indication

For Anxiety:

• Adults: 50-100 mg QID (four times daily) 1
• Initial dose can be 25 mg QID if starting conservatively
• Total daily dose: 50-400 mg

For Pruritus/Itching:

• Adults: 25 mg TID or QID (three or four times daily) 1
• For mild-to-moderate pruritus: 10-25 mg QID or at bedtime 2
• Total daily dose: 25-100 mg

For Children:

• Under 6 years: 50 mg daily in divided doses 1
• Over 6 years: 50-100 mg daily in divided doses 1

For Sedation (premedication):

• Adults: 50-100 mg 1
• Children: 0.6 mg/kg body weight 1

Clinical Use Algorithm

1. Assess severity and indication:

   • For mild anxiety: Start with 25 mg QID
   • For moderate-severe anxiety: 50 mg QID
   • For mild pruritus: 10-25 mg QID or at bedtime
   • For moderate-severe pruritus: 25 mg QID

2. Adjust based on response:

   • If inadequate response after 1 week, increase dose within recommended range
   • If excessive sedation occurs, reduce dose or change administration timing

3. Monitor for side effects:

   • Sedation/drowsiness (most common) 3, 4
   • Dry mouth
   • Weight gain
   • Loss of concentration

Evidence Quality and Efficacy

Hydroxyzine has demonstrated efficacy for both anxiety and pruritus:

• For generalized anxiety disorder (GAD), hydroxyzine 50 mg/day showed significant anxiolytic effects compared to placebo, with benefits starting in the first week of treatment 4
• In comparative studies, hydroxyzine was more effective than placebo and equivalent to buspirone for anxiety management 5
• For pruritus management, hydroxyzine is recommended as a first-line antihistamine option, particularly for nighttime use due to its sedative properties 2

Special Considerations

Timing of Administration

• For anxiety: Divide doses throughout the day
• For pruritus/itching with sleep disruption: Higher dose at bedtime (25 mg) with lower doses during day if needed 2
• Sedative effects typically appear during the first week and progressively diminish with continued use 4

Liver Disease

• In patients with liver disease, use second-generation antihistamines instead or reduce hydroxyzine dose by 50% 6
• Monitor liver function tests before and during treatment in patients with liver disease 6

Elderly Patients

• Start with lower doses (25 mg) due to increased sensitivity to anticholinergic effects
• Increased risk of falls and cognitive impairment 6

Potential Pitfalls and Caveats

1. Sedation: Most common side effect (28% vs 14% with placebo) 4. Consider timing administration to minimize daytime impairment.

2. Anticholinergic effects: Can cause dry mouth, blurred vision, and urinary retention. Use with caution in elderly patients.

3. Pregnancy: Contraindicated during early pregnancy 6.

4. Drug interactions: Use caution when combining with other CNS depressants.

5. Tolerance: Unlike benzodiazepines, hydroxyzine does not appear to cause dependence or withdrawal symptoms upon discontinuation 4.

6. Duration of treatment: For anxiety, efficacy has been demonstrated for up to 4 weeks of continuous use 4, 5. Long-term efficacy data is limited.

Hydroxyzine offers the advantage of treating both anxiety and pruritus simultaneously when both conditions coexist, with minimal risk of dependence compared to benzodiazepines.