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

Hydroxyzine Dosing and Usage

For anxiety in adults, hydroxyzine should be dosed at 50-100 mg four times daily, while for pruritus (itching), the recommended dose is 25 mg three to four times daily, with both indications supported by FDA labeling and clinical guidelines. 1

Anxiety Treatment

The FDA-approved dosing for symptomatic relief of anxiety and tension is 50-100 mg four times daily in adults. 1

• Clinical trials demonstrate hydroxyzine 50 mg/day is superior to placebo for generalized anxiety disorder (GAD), with significant improvement beginning in the first week of treatment. 2
• The anxiolytic effect is maintained throughout 4 weeks of treatment without rebound anxiety or withdrawal symptoms upon abrupt discontinuation. 2
• Hydroxyzine shows equivalent efficacy to benzodiazepines (bromazepam, chlordiazepoxide) and buspirone for GAD over 3-month treatment periods. 3, 4
• For elderly or debilitated patients, start with lower doses and monitor closely for confusion, over-sedation, and fall risk. 5

Pruritus (Itching) Treatment

For allergic conditions causing itching (chronic urticaria, atopic dermatitis, contact dermatoses), the FDA-approved dose is 25 mg three to four times daily in adults. 1

• The British Journal of Dermatology recommends 10-50 mg at bedtime as a sedating antihistamine for patients with pruritus, used as an adjunct to non-sedating antihistamines during the day. 6
• For urticaria specifically, adding hydroxyzine at night (10-50 mg) to daytime non-sedating antihistamines improves sleep and symptom control. 5
• For immune checkpoint inhibitor-related pruritus, hydroxyzine 10-25 mg four times daily or at bedtime can be combined with topical corticosteroids. 7, 6

Pediatric Dosing

• Children under 6 years: 50 mg daily in divided doses for both anxiety and pruritus. 1
• Children over 6 years: 50-100 mg daily in divided doses for both anxiety and pruritus. 1

Special Population Adjustments

Renal Impairment

• Moderate renal insufficiency (creatinine clearance 10-20 mL/min): Reduce dose by half. 6, 5
• Severe renal impairment (creatinine clearance <10 mL/min): Avoid hydroxyzine entirely. 5

Hepatic Impairment

• Severe hepatic disease: Avoid hydroxyzine due to inappropriate sedating effects. 6, 5

Elderly Patients

• Start with lower doses due to increased sensitivity to psychomotor impairment and sedation. 5
• Older adults are at high risk for side effects, particularly with pre-existing prostatic hypertrophy, elevated intraocular pressure, or cognitive impairment. 6

Treatment Duration and Monitoring

• Short-term use (2-4 weeks) is appropriate for mild to moderate symptoms. 6
• Extended monotherapy is not recommended; hydroxyzine is best used as a nighttime adjunct to non-sedating antihistamines for long-term management. 6, 5
• Adjust timing so highest drug levels occur when symptoms are anticipated. 5

Common Side Effects and Precautions

• Drowsiness/sleepiness occurs in 80% of patients (higher than diphenhydramine at 50% or promethazine at 60-73%), typically appearing during the first week and progressively diminishing. 2, 6
• Other common side effects include dry mouth (14%), weight gain (12%), and loss of concentration (9%). 2
• Avoid concomitant use with other CNS depressants as this enhances performance impairment and sedation. 6

Contraindications

• Hydroxyzine is contraindicated during early pregnancy. 5
• If antihistamine therapy is absolutely necessary during pregnancy, chlorphenamine is preferred due to its longer safety record. 5

Clinical Advantages

• Hydroxyzine provides better control of rhinorrhea compared to second-generation antihistamines due to its anticholinergic effects. 6
• No organ toxicity or dependency has been demonstrated in clinical experience. 8
• Efficacy is maintained after abrupt discontinuation without rebound or withdrawal symptoms. 2, 3