Hydroxyzine (Atarax) Dosing for a 22.4 kg Child
For a child weighing 22.4 kg, the appropriate hydroxyzine dose is 50 mg daily in divided doses for most indications, or 0.6 mg/kg (approximately 13-14 mg) for preoperative sedation.
Dosing by Indication
For Pruritus (Itching) or Allergic Conditions
- Children under 6 years: 50 mg daily in divided doses
- Children over 6 years: 50-100 mg daily in divided doses 1
Since a 22.4 kg child is typically around 5-7 years old, the dosing depends on their exact age:
- If under 6 years: Give 50 mg total daily divided into 2-4 doses (e.g., 12.5 mg four times daily or 25 mg twice daily)
- If 6 years or older: Can use 50-100 mg total daily in divided doses, starting at the lower end
For Anxiety or Sedation
- Same dosing as above for age-based categories 1
For Preoperative Sedation
- 0.6 mg/kg = approximately 13-14 mg as a single dose 1
Clinical Considerations
The FDA label provides clear weight-independent, age-based dosing 1, which differs from the typical mg/kg approach used for many pediatric medications. This is important because hydroxyzine has a long elimination half-life (7.1 ± 2.3 hours in children, increasing with age) and significant sedative effects 2.
Key Safety Points
- Start at the lower end of the dosing range and adjust based on response 1
- Sedation is the most common side effect - warn caregivers about this, especially regarding activities requiring alertness 1, 2
- Avoid combining with other CNS depressants without dose adjustment 1
- For chronic use (e.g., atopic dermatitis), 0.7 mg/kg three times daily is as effective as higher doses with significantly less sedation 2
Important Caveats
Recent population-based data suggests that repeated prescriptions of hydroxyzine in preschool children may be associated with increased rates of tics, anxiety, and conduct disturbances 3. While causation is not proven, this warrants using the shortest duration necessary and considering alternative therapies for chronic conditions.
For chronic urticaria specifically, evidence shows that adding nighttime hydroxyzine to a second-generation antihistamine does not improve efficacy but does increase daytime somnolence 4. Second-generation antihistamines alone at higher doses may be preferable.
Practical Dosing Example
For a 22.4 kg child over 6 years with allergic pruritus:
- Start with 12.5-25 mg three to four times daily (50-100 mg total daily)
- Can give larger doses at bedtime if nighttime itching is problematic
- Adjust based on symptom control and sedation tolerance