What is the recommended dosage of hydroxyzine (Hydroxyzine HCl) in children?

Hydroxyzine HCl Dosage in Children

For children under 6 years, administer 50 mg daily in divided doses; for children over 6 years, administer 50-100 mg daily in divided doses, with the specific regimen depending on the indication (anxiety/pruritus vs. premedication). 1

Standard Dosing by Indication

For Anxiety and Pruritus (Chronic Urticaria, Atopic Dermatitis)

• Children under 6 years: 50 mg daily in divided doses 1
• Children over 6 years: 50-100 mg daily in divided doses 1
• The syrup formulation facilitates administration in children who have difficulty swallowing tablets 2, 3

For Premedication/Sedation

• All children: 0.6 mg/kg of body weight 1
• This dose is used when hydroxyzine serves as premedication before procedures or following general anesthesia 1

Optimal Dosing for Atopic Dermatitis

Research demonstrates that 0.7 mg/kg three times daily is as effective as higher doses (1.4 mg/kg TID) for pruritus relief while causing significantly less sedation 4. This lower dose achieved:

• Greater than 85% pruritus suppression from 2-12 hours post-dose 4
• Peak serum concentration of 47.4 ng/ml at approximately 2 hours 4
• Mean elimination half-life of 7.1 hours in children 4

Critical Dose Adjustments

Renal Impairment

• Reduce dose by half in patients with renal impairment 2, 3
• Avoid completely in severe renal impairment (creatinine clearance <10 mL/min) 2, 3

Hepatic Impairment

• Avoid hydroxyzine in severe hepatic impairment due to increased sedating effects 2, 3

Important Safety Considerations

Duration of Use

• Limit hydroxyzine to the shortest possible duration in preschool-age children 5
• Repeat prescriptions (versus single prescription) are associated with increased odds ratios for tic disorder (OR 1.55), anxiety (OR 1.34), and conduct disturbance (OR 1.34) in children up to age 10 years 5
• This represents the first study reporting long-term neurodevelopmental concerns with early hydroxyzine use 5

Common Pitfalls

• The primary adverse effect is sedation, which is dose-dependent 4
• Dosage should be adjusted according to the patient's response to therapy 1
• The elimination half-life increases with age (r = 0.83), requiring consideration in older children 4

Toxicity Recognition

• Hydroxyzine toxicity manifests primarily as generalized seizures and sinus tachycardia 6
• Plasma concentrations above 100 micrograms/ml indicate significant toxicity 6