What is the best antihistamine for an older adult with allergies?

Best Antihistamine for Older Adults with Allergies

For older adults with allergies, second-generation antihistamines such as fexofenadine are the best choice due to minimal sedation and anticholinergic effects, with loratadine and desloratadine as good alternatives when used at recommended doses. 1

Second-Generation vs. First-Generation Antihistamines

Why Second-Generation Antihistamines Are Preferred

• Second-generation antihistamines are strongly preferred over first-generation antihistamines in older adults due to significantly less sedation and fewer anticholinergic effects 1
• First-generation antihistamines (like diphenhydramine, chlorpheniramine) should be avoided in older adults due to:
  • Increased sensitivity to psychomotor impairment 1
  • Higher risk of falls, fractures, and subdural hematomas 1
  • Pronounced anticholinergic effects (dry mouth, constipation, urinary retention) 1
  • Potential worsening of comorbid conditions like glaucoma, benign prostatic hypertrophy, and cognitive impairment 1

Best Options Among Second-Generation Antihistamines

Fexofenadine

• Best overall choice for older adults due to:
  • No sedative properties even at higher than FDA-approved doses 1
  • Minimal drug interactions 2
  • Excellent cardiovascular safety profile 2
  • Standard dosing: 60 mg twice daily or 180 mg once daily 1

Loratadine

• Good alternative with:
  • No sedation at recommended doses (10 mg daily) 1, 3
  • Once-daily dosing convenience 4
  • Well-established safety record in elderly patients 2
  • Available over-the-counter 1
  • Caution: May cause sedation at doses exceeding recommendations 1, 3

Desloratadine

• Similar safety profile to loratadine at recommended doses (5 mg daily) 1
• No sedation at standard doses 1
• May cause sedation at higher doses 1
• Prescription only 1

Antihistamines to Use with Caution in Older Adults

Cetirizine

• May cause mild sedation even at recommended doses (13.7% vs 6.3% for placebo) 1
• Consider using at lower doses (5 mg) in adults over 77 years 1
• Use with caution in renal impairment - dose should be halved 1

Intranasal Antihistamines

• Azelastine and olopatadine can be effective for localized nasal symptoms 1
• May cause somnolence (0.9%-11.5%) and bitter taste 1
• Consider for patients with primarily nasal symptoms who don't respond to oral antihistamines 1

Special Considerations for Older Adults

Renal Impairment

• Avoid acrivastine in moderate renal impairment 1
• Reduce doses of cetirizine and levocetirizine by half 1
• Use loratadine and desloratadine with caution in severe renal impairment 1

Hepatic Impairment

• Use loratadine with caution 1
• Avoid mizolastine in significant hepatic impairment 1

Drug Interactions

• Be cautious with concomitant use of:
  • CNS-active substances (alcohol, sedatives, hypnotics, antidepressants) 1
  • Medications that inhibit hepatic metabolism via cytochrome P450 1

Common Pitfalls to Avoid

• Avoid AM/PM dosing regimens that combine second-generation antihistamines in the morning with first-generation antihistamines at night - this strategy is not recommended due to prolonged half-lives of first-generation antihistamines causing daytime impairment 1
• Don't assume all second-generation antihistamines are equally non-sedating - there are important differences in their sedative properties 1
• Avoid exceeding recommended doses in older adults, as this increases risk of side effects 3
• Don't overlook the impact of antihistamines on existing conditions common in older adults (glaucoma, BPH, cognitive impairment) 1