Diphenhydramine Use in Elderly Patients

Age-Related Considerations

• Elderly patients, especially those over 85 years, should receive reduced doses of diphenhydramine due to increased sensitivity to anticholinergic effects, higher risk of cognitive impairment and delirium, and increased risk of falls and sedation 1, 2, 3

Indications and Cautions

• The American Academy of Sleep Medicine recommends against using diphenhydramine for insomnia in adults, and alternative non-sedating antihistamines should be considered for allergic reactions when sedation is a concern 1, 2, 4
• Diphenhydramine may be used for pruritus (itching) in elderly patients, but caution is advised due to the risk of anticholinergic side effects 2

Potential Adverse Effects

• Central nervous system effects of diphenhydramine include confusion, delirium, especially in elderly patients, and impaired psychomotor performance 2, 4
• Anticholinergic effects of diphenhydramine include dry mouth, blurred vision, urinary retention, and constipation 3, 5
• Cardiovascular effects of diphenhydramine include hypotension and tachycardia 5, 6

Monitoring Recommendations

• Patients taking diphenhydramine should be monitored for changes in mental status or excessive sedation, falls risk, urinary retention, and constipation 3, 5, 6

Alternative Considerations

• For insomnia, the American Academy of Sleep Medicine recommends considering doxepin (3-6 mg) or other recommended agents as alternatives to diphenhydramine 1
• For pruritus, topical treatments or non-sedating antihistamines should be considered as alternatives to diphenhydramine 2