Hydroxyzine (Atarax) Dosage and Usage Guidelines
The standard adult dosage of hydroxyzine (Atarax) is 25 mg taken four times daily, with a total daily dose ranging from 10-100 mg depending on the indication and patient factors. 1
Adult Dosing
- For anxiety disorders: 50 mg/day (can be divided into multiple doses) has shown significant anxiolytic effects beginning in the first week of treatment 2
- For urticaria/pruritus: 25 mg four times daily is the standard dose, with dosage forms available in 10,25,50, and 100 mg tablets and 10 mg/5 mL oral solution 1
- For sedation/sleep: 10-50 mg at bedtime can be added to a non-sedating antihistamine regimen to help with sleep in patients with pruritus 1
- For dermatologic conditions: 25 mg four times daily is typically recommended, with adjustments based on response 1
Pediatric Dosing
- Hydroxyzine is not contraindicated in children 12 years and older (use adult dosing) 1
- For younger children with pruritus: 0.7 mg/kg three times daily has been shown to be as effective as higher doses while causing less sedation 3
- Consult product-specific data sheets for dosing in children under 12 years 1
Special Populations
Renal Impairment
- The dose of hydroxyzine should be halved in patients with moderate renal impairment 1
- Avoid use in severe renal impairment (creatinine clearance <10 mL/min) 1
Hepatic Impairment
- Avoid hydroxyzine in severe liver disease due to inappropriate sedating effects 1
Elderly Patients
- Start with low doses in elderly patients (usually at the low end of the dosing range) 4
- Elderly patients are more susceptible to side effects including sedation, cognitive impairment, and anticholinergic effects 1, 4
- Close monitoring is recommended due to increased risk of falls and other complications 4
Pregnancy
- Hydroxyzine is specifically contraindicated during early stages of pregnancy 1
- It is the only antihistamine with this specific contraindication in UK product labeling 1
Administration Considerations
- Hydroxyzine can be taken with or without food
- For sleep disturbances, administration at bedtime is recommended 1
- When used for anxiety, dividing the daily dose may help maintain consistent effects 2
Important Precautions
- QT prolongation risk: Use with caution in patients with risk factors for QT prolongation, congenital long QT syndrome, recent myocardial infarction, uncompensated heart failure, or bradyarrhythmias 4
- CNS depression: Hydroxyzine has potentiating effects when used with other CNS depressants; dosage reduction of concomitant CNS depressants is recommended 4
- Sedation warning: Patients should be cautioned about driving or operating machinery due to potential drowsiness 4, 5
- Anticholinergic effects: May cause dry mouth, constipation, urinary retention, and increased risk of narrow-angle glaucoma 1
Drug Interactions
- Avoid concomitant use with drugs known to prolong QT interval (Class 1A or III antiarrhythmics, certain antipsychotics, antidepressants, and antibiotics) 4
- Use caution when combining with other CNS depressants including alcohol, narcotics, non-narcotic analgesics, and barbiturates 4
Monitoring
- Monitor for sedation, especially during initial treatment 2, 5
- In elderly patients, observe closely for confusion and oversedation 4
- For long-term use, periodic evaluation of continued need is recommended
Hydroxyzine is generally well-tolerated with transient sleepiness being the most common side effect, which often resolves with continued use at the same dosage level 2, 5.