Is doxylamine safe to use in elderly patients?

Doxylamine Safety in Elderly Patients

Doxylamine is generally not safe for elderly patients and should be avoided due to its anticholinergic properties and increased risk of adverse effects in this population. 1

Risks of Doxylamine in Elderly Patients

• Doxylamine is classified as potentially inappropriate for older adults according to the Beers Criteria due to its strong anticholinergic properties 1, 2
• More than half (59%) of older adults taking over-the-counter sleep medications use products containing diphenhydramine or doxylamine, often unaware of their safety risks 2
• Elderly patients are particularly vulnerable to anticholinergic side effects including:
  • Central nervous system impairment (delirium, cognitive impairment, slowed comprehension) 1
  • Visual disturbances 1
  • Urinary retention 1
  • Constipation 1
  • Sedation leading to increased fall risk 1

Pharmacokinetic Considerations

• Elderly men show reduced doxylamine clearance (174 vs 240 ml/min in younger men) and prolonged half-life (15.5 vs 10.2 hours) 3
• While elderly women don't show significant differences in clearance compared to younger women, the anticholinergic risks remain concerning for all elderly patients 3
• Reduced renal function and medication clearance in elderly patients increases susceptibility to drug accumulation and narrows the therapeutic window between safe dosages and those associated with adverse effects 1

Safer Alternatives for Elderly Patients

• For insomnia in elderly patients, non-pharmacological approaches should be considered first 1
• If medication is necessary for sleep:
  • Low-dose regimens should be explored specifically for elderly patients 1
  • Regular acetaminophen on a scheduled basis may help with pain-related sleep disturbances 1
  • When pharmacological treatment is necessary, medications with the lowest side effect profile for geriatric patients should be selected 1

Recommendations for Clinicians

• Comprehensive assessment of elderly patients for declining function before prescribing any anticholinergic medications 1
• Use additional caution and increased monitoring when prescribing any medications with anticholinergic properties to patients aged ≥65 years 1
• Consider the cumulative anticholinergic burden when prescribing to elderly patients, as many may already be taking other medications with anticholinergic properties 1, 4
• Implement interventions to mitigate common risks in older adults, such as fall risk assessment and monitoring for cognitive impairment 1

Special Considerations

• Polypharmacy increases the risk of adverse drug reactions in elderly patients 5
• Elderly patients with cognitive impairment are at even higher risk for medication errors and confusion from anticholinergic medications 1
• Clinical pharmacist involvement in medication management can help reduce medication errors in elderly patients 1

In conclusion, doxylamine should generally be avoided in elderly patients due to its anticholinergic properties and the increased risk of adverse effects in this population. Safer alternatives and non-pharmacological approaches should be prioritized for managing insomnia in older adults.