What is the appropriate dosage and usage of hydroxyzine for treating anxiety in adults and children with varying medical histories?

Hydroxyzine Dosing and Clinical Use

Primary Recommendation

Hydroxyzine is not a first-line treatment for anxiety disorders in adults or children; SSRIs and SNRIs should be prioritized based on robust evidence, with hydroxyzine reserved for specific scenarios like pruritus management, procedural anxiolysis, or as adjunctive therapy when first-line treatments are inadequate. 1, 2

Clinical Positioning

• Hydroxyzine is notably absent from major anxiety disorder treatment guidelines (NICE, S3, Canadian CPG, AACAP 2020) as a recommended agent for generalized anxiety disorder 2
• First-line treatments for GAD remain SSRIs and SNRIs based on robust evidence and guideline recommendations 1, 2
• A Cochrane review concluded that despite being more effective than placebo, the high risk of bias in studies, small sample sizes, and limited number of trials prevent recommending hydroxyzine as a reliable first-line treatment in GAD 3

FDA-Approved Dosing

For Anxiety and Tension (Psychoneurosis)

• Adults: 50-100 mg four times daily 4
• Children under 6 years: 50 mg daily in divided doses 4
• Children over 6 years: 50-100 mg daily in divided doses 4

For Pruritus (Allergic Conditions)

• Adults: 25 mg three to four times daily 4
• Children under 6 years: 50 mg daily in divided doses 4
• Children over 6 years: 50-100 mg daily in divided doses 4

For Procedural Sedation

• Adults: 50-100 mg 4
• Children: 0.6 mg/kg body weight 4

Alternative Dosing Strategies from Guidelines

• For urticaria with sleep disturbance: 10-50 mg at bedtime combined with a non-sedating antihistamine during the day 5, 6
• For anxiety management (when used): 10-50 mg per dose, though not first-line 5
• Adjust timing so highest drug levels occur when symptoms are anticipated 6

Critical Safety Considerations and Contraindications

Absolute Contraindications

• Early pregnancy: Hydroxyzine is specifically contraindicated; if antihistamine therapy is absolutely necessary during pregnancy, chlorphenamine is preferred 5, 6

Severe Warnings

• Significant sedative effects can impair driving ability, work performance, and cognitive function 5
• Drivers in fatal accidents are 1.5 times more likely to be taking first-generation antihistamines 5
• Performance impairment can occur without subjective awareness of drowsiness 5
• Recent data shows hydroxyzine became the most identified antihistamine in impaired driving investigations in 2023, outpacing diphenhydramine 7

Avoid or Use with Extreme Caution

• Severe liver disease: Avoid due to inappropriate sedating effects 5, 6
• Severe renal impairment (CrCl <10 mL/min): Avoid entirely 5, 6
• Moderate renal impairment (CrCl 10-20 mL/min): Reduce dose to half the standard dose 5, 6

Elderly Patients

• Start with low doses and monitor closely for confusion, over-sedation, and fall risk 5, 6
• Elderly patients have increased sensitivity to psychomotor impairment and are at increased risk for falls, fractures, and anticholinergic effects 5

Common Adverse Effects

• Sedation, drowsiness, and sleepiness (most common) 1, 5
• Weakness 1
• Impaired memory and concentration 7
• Anticholinergic effects in elderly 5

Specific Clinical Scenarios Where Hydroxyzine May Be Appropriate

Interstitial Cystitis/Bladder Pain Syndrome

• Oral hydroxyzine has shown clinically significant improvement compared to placebo (Evidence Strength: Grade C) 1
• Patients with systemic allergies may be more likely to respond 1
• Adverse effects are common but generally not serious (short-term sedation, weakness) 1

Procedural Anxiolysis in Pediatrics

• Hydroxyzine is approved and practical for anxiolysis during medical procedures in pediatric populations 2

Benzodiazepine Withdrawal Support

• Hydroxyzine 25-50 mg can be used as transient support during lorazepam withdrawal 8
• Hydroxyzine 50 mg showed significant improvement in anxiety and reduction of withdrawal symptoms 8

Adjunctive Uses

• Opioid-induced pruritus and nausea (adjunctive treatment) 5
• Chemical restraint in agitated patients (children and adolescents), though PRN use is prohibited per JCAHO standards 2, 5

Critical Clinical Pitfalls to Avoid

• Do not use hydroxyzine as PRN chemical restraint: This practice is prohibited per JCAHO standards 2
• Do not assume patients are aware of their impairment: Performance impairment can occur without subjective drowsiness 5
• Do not combine with cell phone use while driving: Impaired driving performance with hydroxyzine worsens with concurrent activities 5
• Do not prescribe without counseling on driving risks: Patients must be warned about significant impairment of driving ability 5, 7

Drug Combinations

• Common combinations in impaired driving cases: Antidepressants (74%), opioids (44%), and anticonvulsants (38%) 7
• For urticaria: Can combine with non-sedating antihistamine (e.g., loratadine 10 mg morning, hydroxyzine 10-50 mg bedtime) 5

When to Choose Alternative Treatments

• For daytime anxiety management: Second-generation antihistamines or SSRIs/SNRIs are preferred due to reduced sedative effects 5
• For GAD as primary disorder: SSRIs and SNRIs remain first-line based on guideline recommendations 1, 2
• When driving or operating machinery is required: Avoid hydroxyzine due to significant impairment risk 5, 7