What are the considerations for using hydroxyzine (antihistamine) in elderly patients?

Hydroxyzine Use in Elderly Patients: Considerations and Precautions

Hydroxyzine should be avoided in elderly patients due to its strong anticholinergic properties, increased risk of falls, cognitive impairment, and sedation. 1, 2

Risks of Hydroxyzine in Elderly Patients

Anticholinergic Effects

• Hydroxyzine is classified as an "old antihistamine" with strong anticholinergic properties that can cause:
  • CNS impairment including delirium and slowed comprehension
  • Vision impairment
  • Urinary retention
  • Constipation
  • Sedation
  • Increased fall risk 1

Sedation and Cognitive Impairment

• Hydroxyzine has a high sedative potential (80%) compared to second-generation antihistamines 3
• Sedative antihistamines used long-term may predispose elderly patients to dementia 3
• First-generation antihistamines significantly increase the risk of injurious falls or fractures in elderly patients (OR 2.03,95% CI 1.49-2.76) 4

FDA Warnings for Elderly Patients

• The FDA label specifically cautions about hydroxyzine use in elderly patients:
  • "Sedating drugs may cause confusion and over-sedation in the elderly"
  • "Elderly patients generally should be started on low doses of hydroxyzine and observed closely"
  • "Elderly patients are more likely to have decreased renal function, requiring dose adjustments" 2

Additional Safety Concerns

QT Prolongation Risk

• Hydroxyzine can cause QT prolongation and Torsade de Pointes
• Use with caution in patients with:
  • Pre-existing heart disease
  • Electrolyte imbalances
  • Concomitant use of other QT-prolonging medications
  • Congenital long QT syndrome
  • Recent myocardial infarction
  • Uncompensated heart failure
  • Bradyarrhythmias 2

Drug Interactions

• Potentiates CNS depressants including narcotics, non-narcotic analgesics, and barbiturates
• Caution with medications that prolong QT interval (antiarrhythmics, certain antipsychotics, antidepressants, antibiotics) 2

Alternative Treatment Options

Preferred Antihistamines for Elderly

• Second-generation antihistamines are strongly preferred over first-generation antihistamines like hydroxyzine 3
• Options with lower sedation potential:
  • Fexofenadine (1.3% sedation)
  • Desloratadine (2.1% sedation)
  • Loratadine (8% sedation) 3

Non-Pharmacological Approaches

• For pruritus management:
  • High lipid content moisturizers applied daily
  • Topical hydrocortisone for localized areas 3

Special Circumstances

While one small study (n=12) suggested that hydroxyzine 25mg might preserve memory and attention better than lorazepam in elderly subjects 5, this finding is outweighed by the substantial evidence of risks documented in larger studies and clinical guidelines.

Monitoring if Use Cannot Be Avoided

If hydroxyzine must be used in an elderly patient due to lack of alternatives:

• Start at the lowest possible dose
• Use for the shortest duration possible
• Monitor closely for:
  • Confusion
  • Sedation
  • Falls
  • QT prolongation
  • Anticholinergic side effects 2

The American Geriatrics Society explicitly lists hydroxyzine among medications that should be avoided in older adults due to its high risk of delirium and other adverse outcomes 1. The strong recommendation to avoid hydroxyzine in elderly patients is based on its inclusion in the Beers Criteria of Potentially Inappropriate Medications for older adults.