Maximum Daily Dose of Hydroxyzine
The maximum recommended dose of hydroxyzine is 400 mg per day in divided doses for adults, though typical therapeutic dosing ranges from 200-300 mg daily depending on the indication. 1
FDA-Approved Dosing by Indication
For Anxiety and Tension
- Adults: 50-100 mg four times daily (200-400 mg/day total) 1
- Children under 6 years: 50 mg daily in divided doses 1
- Children over 6 years: 50-100 mg daily in divided doses 1
For Pruritus (Allergic Conditions)
- Adults: 25 mg three to four times daily (75-100 mg/day total) 1
- Children under 6 years: 50 mg daily in divided doses 1
- Children over 6 years: 50-100 mg daily in divided doses 1
For Sedation/Premedication
Clinical Trial Evidence Supporting Dosing
Research studies have consistently used 50 mg daily for generalized anxiety disorder, demonstrating efficacy at this lower dose with acceptable tolerability 2, 3. One study used 100 mg daily (combined with caffeine to reduce sedation) in multiple sclerosis patients without significant safety concerns 4.
Important Safety Considerations
- Sedation is dose-dependent: The most common side effect is drowsiness, occurring in approximately 28% of patients at 50 mg/day, which typically appears during the first week and progressively diminishes 2
- Dosage should be adjusted according to the patient's response to therapy, as emphasized in the FDA labeling 1
- CNS depression effects: Hydroxyzine can cause fatigue, sedation, impaired memory, concentration difficulties, and driving impairment, particularly when combined with other CNS depressants 5
- Drug interactions: In DUID investigations, 74% of hydroxyzine-positive cases involved concurrent antidepressants, 44% involved opioids, and 38% involved anticonvulsants 5
Practical Dosing Algorithm
Start low and titrate based on indication:
- For pruritus: Begin with 25 mg TID-QID (75-100 mg/day) 1
- For anxiety: Begin with 50 mg/day and may increase to 50-100 mg QID if needed (up to 400 mg/day maximum) 1
- For dermatitis: Use 10-25 mg QID or at bedtime as adjunctive therapy 6
The practical maximum in clinical practice is typically 300 mg/day in divided doses, though the FDA label permits up to 400 mg/day for anxiety when clinically necessary 1.