Maximum Single Dose of Vistaril (Hydroxyzine) for Anxiety
The maximum single dose of hydroxyzine (Vistaril) for anxiety in adults is 100 mg per dose, as indicated by the FDA label. 1
Dosing Guidelines for Adults
- For anxiety and tension relief, adults should receive 50 to 100 mg four times daily (q.i.d.), with a maximum single dose of 100 mg 1
- The total maximum daily dose for anxiety in adults is 400 mg, divided throughout the day 1
- Onset of action is relatively quick compared to some other anxiolytics like buspirone 2
Special Populations
- For elderly or debilitated patients, lower doses are recommended (25-50% reduction) due to increased risk of sedation and other side effects 2
- Dosage should be adjusted according to the individual patient's response to therapy 1
- When transitioning from intramuscular administration, subsequent doses may be administered orally 1
Side Effects and Precautions
- Hydroxyzine can cause significant sedation and drowsiness, which is more pronounced than with other anxiolytic agents 3, 4
- Caution should be exercised when combining hydroxyzine with other CNS depressants, particularly benzodiazepines, as this may increase sedation 2
- Hydroxyzine has been associated with impaired driving performance and psychomotor function, with mean blood concentrations of 70 ±79 ng/mL observed in driving under the influence cases 5
Clinical Considerations
- Hydroxyzine has shown efficacy in treating generalized anxiety disorder compared to placebo in clinical trials 4
- Unlike benzodiazepines, hydroxyzine does not appear to interfere with the efficacy of SSRI antidepressants when co-administered 6
- Common adverse effects include drowsiness, dizziness, dry mouth, and nervousness 3
- While effective for short-term anxiety relief, the evidence for long-term use is limited 3
Practical Administration Tips
- When initiating treatment, starting at lower doses (such as 25-50 mg) and titrating up based on response and tolerability may help minimize side effects 1
- For maximum effectiveness in managing acute anxiety symptoms, hydroxyzine can be taken as needed within the prescribed dosing limits 1
- Monitor for excessive sedation, especially when starting therapy or increasing doses 5