What is the recommended dose of Atarax (hydroxyzine) for itching?

Hydroxyzine Dosage for Itching

For the management of pruritus due to allergic conditions, the recommended dose of hydroxyzine is 25 mg three times daily (t.i.d.) or four times daily (q.i.d.) for adults. 1

Adult Dosing Guidelines

• For pruritus management in adults, hydroxyzine is typically prescribed at 25 mg t.i.d. or q.i.d. (75-100 mg total daily dose) 1
• For nighttime itching, hydroxyzine's sedative properties make it particularly useful as a bedtime medication at doses of 10-50 mg 2
• Higher doses (up to 50 mg q.i.d.) may be considered for severe or refractory pruritus, especially in urticaria 2
• In clinical practice, hydroxyzine is often combined with a non-sedating antihistamine for daytime use, with hydroxyzine reserved for nighttime to minimize daytime sedation 3

Pediatric Dosing

• For children under 6 years: 50 mg total daily dose divided into multiple administrations 1
• For children over 6 years: 50-100 mg total daily dose divided into multiple administrations 1
• In children with atopic dermatitis, a dose of 0.7 mg/kg three times daily has shown similar efficacy to higher doses with less sedation 4

Clinical Efficacy

• Hydroxyzine has demonstrated significant efficacy in reducing pruritus in various conditions including:

  • Chronic urticaria (47% reduction in symptom scores) 5
  • Atopic dermatitis (38% reduction in symptom scores) 5
  • Generalized pruritus of unknown origin 3

• The onset of antipruritic effect occurs within 1-2 hours after oral administration, with peak effect at 2-4 hours 4

• Significant pruritus suppression can last up to 24 hours, with >85% suppression from 2-12 hours after administration 4

Special Considerations

• Elderly patients: Lower doses are recommended due to increased risk of anticholinergic effects and sedation 3
• Renal impairment: Dose should be reduced by 50% in moderate renal impairment 3
• Liver disease: Use with caution due to risk of inappropriate sedation 3
• Pregnancy: Generally contraindicated, especially in early stages 3

Common Side Effects

• Sedation/somnolence is the most common side effect, reported in approximately 40% of patients (compared to 5% with newer antihistamines like loratadine) 5
• Other potential side effects include dry mouth, dizziness, and constipation 2

Alternative Options

• For patients who cannot tolerate hydroxyzine's sedative effects, second-generation non-sedating antihistamines (cetirizine, loratadine, fexofenadine) are alternatives for daytime use 3
• Cetirizine (the active metabolite of hydroxyzine) may be used at doses of 10-40 mg daily for urticaria and atopic dermatitis with less sedation 6
• For severe or refractory urticaria, adding a short course of oral corticosteroids (e.g., prednisone) to antihistamine therapy may provide more rapid and complete symptom relief 7

Practical Tips

• Start with lower doses (e.g., 25 mg) and titrate based on response and tolerability 2
• Advise patients about potential sedation and to avoid driving or operating machinery until they know how the medication affects them 3
• Hydroxyzine not only blocks histamine receptors but also may inhibit histamine release from mast cells, providing dual mechanism of action against pruritus 8
• For maximum benefit in chronic pruritus, combine with general measures such as avoiding overheating, stress, alcohol, and using cooling lotions (e.g., calamine or 1% menthol in aqueous cream) 2