Is IV Diphenhydramine (Benadryl) safe for sleep in elderly patients?

IV Diphenhydramine (Benadryl) Should Not Be Used for Sleep in Elderly Patients

IV diphenhydramine (Benadryl) should be avoided for sleep in elderly patients due to significant safety concerns and lack of efficacy evidence. 1, 2

Safety Concerns with IV Diphenhydramine in Elderly

• Antihistamines like diphenhydramine are more likely to cause dizziness, sedation, and hypotension in elderly patients, making them particularly dangerous in this population 1
• The FDA drug label specifically cautions about use in elderly patients (approximately 60 years or older) due to increased sensitivity to adverse effects 1
• Diphenhydramine has anticholinergic properties that can cause significant adverse effects in older adults, including:
  • Dry mouth, blurred vision, and urinary retention 1, 2
  • Cognitive impairment and increased risk of delirium 2, 3
  • Increased risk of falls and injuries 2, 3

Guideline Recommendations Against Use

• The American Geriatrics Society recommends avoiding antihistamines, including diphenhydramine, in elderly patients for sleep 4, 5
• The 2005 NIH State-of-Science Conference on Insomnia concluded that there is no systematic evidence for the effectiveness of antihistamines for insomnia and warned that the risks outweigh the benefits 4
• The American Academy of Sleep Medicine does not recommend diphenhydramine for the treatment of insomnia 6

Preferred Alternatives for Sleep in Elderly

• Non-pharmacological interventions should be first-line treatment for insomnia in elderly patients:

  • Cognitive Behavioral Therapy for Insomnia (CBT-I) has been shown to be highly effective 4
  • Sleep hygiene education, including maintaining regular sleep schedules 6
  • Stimulus control and sleep restriction techniques 4

• If medication is necessary, safer alternatives include:

  • Ramelteon (8mg) for sleep onset insomnia, which has minimal adverse effects and is recommended by the American Academy of Sleep Medicine 6, 5
  • Low-dose doxepin (3-6mg) for sleep maintenance insomnia 6, 5

Prevalence of Inappropriate Use

• Despite recommendations against use, studies show that more than half (59%) of older adults taking over-the-counter sleep medications use products containing diphenhydramine or doxylamine 3
• Many older adults are unaware of the safety risks associated with these medications 3

Drug Interactions and Additional Concerns

• Diphenhydramine has additive effects with alcohol and other CNS depressants, increasing risk of adverse outcomes 1
• Elderly patients often take multiple medications, increasing the potential for dangerous drug interactions 7
• The IV formulation may pose additional risks compared to oral formulations, including more rapid onset of side effects and potential for local tissue damage 1

Summary of Evidence

• A systematic review of over-the-counter sleep medications in older adults found that while diphenhydramine showed some efficacy for sleep, its safety profile makes it unsuitable for elderly patients 8
• The 2015 Beers Criteria for Potentially Inappropriate Medication Use in Older Adults specifically recommends that individuals 65 years or older avoid use of diphenhydramine 3

When treating insomnia in elderly patients, always prioritize non-pharmacological approaches first, and if medication is necessary, choose agents specifically recommended for geriatric populations rather than diphenhydramine, which carries significant risks with limited evidence of benefit 4, 2.