What is the recommended dosage and treatment regimen for hydroxyzine in adults with anxiety and itching?

Hydroxyzine Dosage and Treatment Regimen for Anxiety and Pruritus in Adults

For adults with anxiety and pruritus, hydroxyzine is recommended at 25-50 mg daily in divided doses, with first-generation antihistamines like hydroxyzine particularly useful at 25-50 mg daily for nighttime pruritus due to their sedative properties. 1

Dosage Recommendations by Indication

For Pruritus/Itching:

• Standard adult dosage: 25 mg three to four times daily 2
• Nighttime pruritus: 25-50 mg at bedtime (particularly beneficial due to sedative properties) 1
• Treatment duration: Short-term use is preferred to minimize side effects

For Anxiety:

• Standard adult dosage: 50-100 mg four times daily 2
• Alternative regimen: 50 mg/day has shown efficacy in clinical trials for generalized anxiety disorder 3, 4
• Treatment duration: Efficacy demonstrated in trials up to 12 weeks 4

Treatment Algorithm

1. Initial Assessment:

   • Determine primary indication (anxiety, pruritus, or both)
   • Evaluate severity of symptoms
   • Check for contraindications (severe hepatic impairment, pregnancy)

2. For Pruritus:

   • First-line approach:
     • Start with 25 mg three times daily for daytime itching 2
     • For nighttime pruritus: 25-50 mg at bedtime 1
   • For inadequate response:
     • May increase to maximum of 25 mg four times daily
     • Consider adding non-sedating antihistamine during daytime (e.g., loratadine 10 mg daily) 1

3. For Anxiety:

   • First-line approach: 50 mg/day in divided doses 3
   • For inadequate response: May increase up to 50-100 mg four times daily 2
   • Monitoring: Assess efficacy within 1-2 weeks (improvement should be evident by first week) 3

4. For Combined Anxiety and Pruritus:

   • Start with 25 mg three times daily with 50 mg at bedtime
   • Adjust based on predominant symptom and response

Special Considerations

Renal Impairment

• In moderate renal impairment: Reduce dose by 50% 1
• In severe renal impairment (creatinine clearance <10 mL/min): Avoid use 1

Hepatic Impairment

• Avoid in severe liver disease due to increased sedative effects 1

Elderly Patients

• Start at lower doses (25 mg daily) and titrate slowly
• Consider gabapentin as alternative for elderly patients with pruritus 1

Potential Side Effects and Management

• Common side effects: Drowsiness/sleepiness (28% vs 14% with placebo), dry mouth (14% vs 5%), weight gain (12% vs 10%) 3
• Onset of side effects: Sleepiness typically appears during first week and progressively diminishes 3
• Management: Take largest dose at bedtime to minimize daytime sedation

Important Cautions

• Hydroxyzine is contraindicated during early pregnancy 1
• Avoid long-term use when possible due to sedative effects
• Do not combine with other CNS depressants
• Sedation may impair driving ability and operation of machinery
• First-generation antihistamines like hydroxyzine should be avoided in severe liver disease 1

Treatment Duration

• For acute pruritus: Short-term use (days to weeks)
• For anxiety: Efficacy maintained throughout 4 weeks of treatment without rebound anxiety after discontinuation 3
• Longer-term use (up to 12 weeks) has shown continued efficacy and safety in anxiety 4

Hydroxyzine provides both antihistaminic effects for pruritus and anxiolytic benefits, making it particularly useful when both conditions coexist, with the added benefit of sedation for nighttime symptoms.