Hydroxyzine Dosing for Anxiety
For generalized anxiety disorder in adults, the recommended dose is 50-100 mg four times daily (QID), as specified by the FDA label, though starting at 50 mg daily and titrating based on response is a practical approach supported by clinical trial evidence. 1
Standard Dosing Regimens
Adults with Generalized Anxiety Disorder
- FDA-approved dosing: 50-100 mg four times daily (QID) for symptomatic relief of anxiety and tension associated with psychoneurosis 1
- Evidence-based alternative: 50 mg once daily has demonstrated efficacy in multiple controlled trials, with significant anxiolytic effects beginning within the first week of treatment 2, 3
- Onset of action: 15-30 minutes after oral administration, with effects lasting 4-6 hours 4, 5
Special Populations
Elderly patients or those sensitive to sedation:
- Start with 25 mg daily and titrate cautiously 4, 5
- Elderly patients are particularly susceptible to anticholinergic effects and sedation 6
- Dose should be halved in moderate renal impairment 6
Patients with comorbid insomnia:
- Bedtime dosing of 50-100 mg provides dual benefits for anxiety and sleep disturbance 4, 5
- The sedative properties make hydroxyzine particularly useful when both conditions coexist 4
Pediatric dosing (per FDA label):
- Children under 6 years: 50 mg daily in divided doses 1
- Children over 6 years: 50-100 mg daily in divided doses 1
Clinical Considerations
Efficacy Profile
- Hydroxyzine demonstrates superiority over placebo on all anxiety measures from week 1, with particular effectiveness on cognitive components of anxiety 7, 2
- A 3-month trial showed mean HAM-A score reduction of 12.16 points versus 9.64 for placebo (p=0.019) 3
- Efficacy is maintained throughout treatment and after abrupt discontinuation without rebound anxiety or withdrawal symptoms 2, 3
Advantages Over Benzodiazepines
- No dependency or withdrawal issues, unlike benzodiazepines 7
- Comparable efficacy to bromazepam (6 mg/day) in 3-month trials 3
- May provide better control of somatic anxiety symptoms (trembling, physical tension) due to anticholinergic effects 4, 5
Common Side Effects
- Drowsiness/sleepiness is the most common side effect (28% vs 14% placebo), typically appearing in the first week and progressively diminishing 2
- Other effects include dry mouth (14%), weight gain (12%), and loss of concentration (9%) 2
- Drowsiness is more frequent at 50 mg compared to 25 mg dosing 8
Critical Contraindications and Precautions
Absolute contraindications:
- Early pregnancy (specifically contraindicated per UK manufacturer guidelines) 6
- Closed-angle glaucoma 4, 5
- Prostatic hypertrophy 4, 5
- Severe liver disease (may precipitate coma) 6
- Severe renal impairment (creatinine clearance <10 mL/min) 6
Use with extreme caution in:
- Elderly patients due to anticholinergic burden 6, 4, 5
- Patients with cognitive impairment 5
- Hepatic impairment (avoid in severe cases) 6
Practical Dosing Algorithm
Initial assessment: Verify no contraindications (pregnancy, glaucoma, severe hepatic/renal disease) 6, 4, 5
Starting dose selection:
Titration: Adjust dose according to patient response after 1 week, as anxiolytic effects should be evident by this time 2, 3
Maintenance: Continue effective dose for duration needed; studies support safe use up to 3 months 3
Discontinuation: Can be stopped abruptly without tapering, as no withdrawal syndrome or rebound anxiety occurs 2, 3
Important Clinical Pitfalls
- Do not use as monotherapy for major depressive disorder—hydroxyzine does not constitute adequate treatment for comorbid depression 4
- Monitor for paradoxical agitation, particularly in younger patients, though this is rare 4
- Avoid concurrent use with other anticholinergic medications in elderly patients to prevent cumulative anticholinergic burden 6
- Transient drowsiness in week 1 is expected and typically resolves—counsel patients accordingly to improve adherence 2