What is the lowest dose of Atarax (hydroxyzine) for adults?

Lowest Dose of Hydroxyzine (Atarax) for Adults

The lowest dose of hydroxyzine (Atarax) for adults is 10 mg, which can be given up to four times daily. 1

Dosage Information

Hydroxyzine is available in various dosage forms and strengths. According to the FDA-approved labeling, the dosing varies based on the indication:

• For anxiety and tension: 50-100 mg four times daily 2
• For pruritus (itching) due to allergic conditions: 25 mg three to four times daily 2
• For sedation (premedication): 50-100 mg 2
• For sleep induction in patients with pruritus: 10-50 mg at bedtime 1

Dosage Considerations

Age and Population Factors

• Elderly patients should be started at the lowest possible dose (10 mg) due to increased sensitivity to psychomotor impairment and higher risk of complications such as falls 3
• Patients with renal impairment:
  • Moderate impairment: The dose should be halved 1
  • Severe impairment: Hydroxyzine should be avoided 1
• Patients with severe liver disease should use hydroxyzine with caution or avoid it altogether 1

Clinical Considerations

When determining the appropriate starting dose, consider:

1. Indication for use - anxiety requires higher doses than pruritus management
2. Patient's age - older adults are more sensitive to side effects
3. Time of day - sedating effects may be beneficial at night but problematic during the day
4. Concomitant medications - potential for additive sedative effects

Side Effects and Precautions

Hydroxyzine is a first-generation antihistamine with significant anticholinergic effects that may cause:

• Sedation/drowsiness - more common than with other anxiolytics 4
• Cognitive impairment - can affect learning, school performance in children, and driving ability 1
• QT interval prolongation - caution in patients with cardiac conditions 5

Important Warnings

• Concomitant use with alcohol, sedatives, hypnotics, or antidepressants may enhance performance impairment 1
• Even small doses (12.5 mg) have been reported to cause QT prolongation and torsade de pointes in susceptible individuals, particularly those with bradycardia 5
• Unlike second-generation antihistamines, hydroxyzine significantly prolongs both simple and choice reaction times 6

Titration Approach

For most adults requiring hydroxyzine:

1. Start with the lowest effective dose (10 mg)
2. Assess response and tolerability
3. Titrate upward as needed based on clinical response
4. Adjust timing of doses based on when sedation would be beneficial vs. problematic

For anxiety management specifically, clinical studies have shown efficacy at 50 mg/day divided doses, with anxiolytic effects beginning during the first week of treatment 7. However, starting at a lower dose and titrating up is recommended to minimize side effects.