What is the recommended dose of Syr Atarax (hydroxyzine) for a 10-month-old baby weighing 8.5 kg?

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Hydroxyzine (Atarax) Dosing for a 10-Month-Old Baby Weighing 8.5 kg

For a 10-month-old baby weighing 8.5 kg, the appropriate dose of hydroxyzine syrup (10mg/5mL) is 0.6 mg/kg, which equals approximately 5.1 mg (2.55 mL) per dose. 1

Dosage Calculation

  • The FDA-approved dosage for hydroxyzine in children under 6 years is 0.6 mg/kg of body weight when used as a sedative 1
  • For this 10-month-old weighing 8.5 kg:
    • 0.6 mg/kg × 8.5 kg = 5.1 mg per dose
    • Using 10mg/5mL concentration: 5.1 mg ÷ (10mg/5mL) = 2.55 mL per dose 1

Administration Guidelines

  • Hydroxyzine can be administered in divided doses throughout the day, typically 2-3 times daily depending on the indication 1
  • When initiating treatment, start with the calculated dose and adjust according to the patient's response to therapy 1
  • Consider giving the medication with food to improve gastrointestinal tolerability 2

Monitoring and Safety Considerations

  • Monitor for sedation, which is the most common adverse effect reported in pediatric patients 3
  • The elimination half-life of hydroxyzine in children increases with age, with a mean of approximately 7.1 hours 3
  • Hydroxyzine may cause CNS depressant effects including fatigue, sedation, and impaired concentration 4
  • In pediatric studies, hydroxyzine at 0.7 mg/kg provided significant symptom relief with minimal sedation compared to higher doses 3

Clinical Efficacy

  • Hydroxyzine has been shown to be effective for various indications including:
    • Management of pruritus due to allergic conditions 1, 3
    • Symptomatic relief of anxiety 1, 5
    • Premedication sedation 1

Important Precautions

  • Avoid exceeding the recommended dose as this may increase the risk of adverse effects 2
  • Be aware that hydroxyzine may cause more pronounced sedation in younger children 3
  • Complete the full course of medication as prescribed, even if symptoms improve before completion 2
  • If excessive sedation occurs, consider reducing the dose while maintaining therapeutic effect 3

References

Guideline

Pediatric Medication Dosing Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Hydroxyzine in Impaired Driving Investigations.

Journal of analytical toxicology, 2025

Research

Hydroxyzine for generalised anxiety disorder.

The Cochrane database of systematic reviews, 2010

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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