What are the concerns with using meclizine in geriatric patients?

Concerns with Using Meclizine in Geriatric Patients

Meclizine should be used with extreme caution in geriatric patients due to its anticholinergic properties, which can cause significant cognitive impairment, delirium, sedation, and increased fall risk. 1

Anticholinergic Burden

Meclizine is classified as a first-generation antihistamine with significant anticholinergic effects. According to the Mayo Clinic guidelines on polypharmacy management in older adults, medications with anticholinergic properties pose specific risks in the geriatric population 1:

• Central nervous system impairment including:

  • Delirium
  • Cognitive slowing
  • Sedation
  • Increased fall risk

• Peripheral anticholinergic effects:

  • Visual impairment
  • Urinary retention
  • Constipation

Medication Considerations in Geriatrics

FDA Labeling Guidance

The FDA label for meclizine specifically addresses concerns in geriatric patients 2:

• "Dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range"
• This caution reflects "greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy"
• Meclizine undergoes metabolism via CYP2D6, and hepatic impairment may result in increased systemic exposure

Pharmacokinetic Considerations

Geriatric patients have altered pharmacokinetics that affect meclizine handling 2, 3:

• Potential for drug/metabolite accumulation due to declining renal function with age
• Changes in body composition (decreased water content, increased fat content) affecting drug distribution
• Reduced metabolic clearance, especially pronounced in malnourished or frail patients

Risk of Drug Interactions

Meclizine poses significant drug interaction risks in geriatric patients who often take multiple medications 2:

• Increased CNS depression when administered with other CNS depressants, including alcohol
• Potential interactions with CYP2D6 inhibitors, which may increase meclizine exposure
• Polypharmacy concerns - 40% of patients over 65 take 5-9 medications daily, and 18% take more than 10 medications 1

Deprescribing Considerations

Several geriatric guidelines specifically identify first-generation antihistamines like meclizine as potentially inappropriate medications (PIMs) in older adults 1:

• The Beers Criteria recommends avoiding or tapering these medications when possible
• These medications are listed in deprescribing guidelines for frail elderly patients
• Anticholinergic medications are prime targets for deprescribing in polypharmacy management

Practical Approach to Meclizine Use in Geriatrics

If meclizine must be used in geriatric patients:

1. Start at the lowest possible effective dose (typically 12.5mg rather than 25mg or 50mg)

2. Use for the shortest duration necessary

3. Monitor closely for:

   • Changes in cognition or mental status
   • New or worsening confusion
   • Falls or unsteady gait
   • Urinary retention or constipation
   • Blurred vision

4. Consider safer alternatives when possible, particularly for vertigo or motion sickness

Conclusion

When prescribing for geriatric patients, the anticholinergic burden of meclizine presents significant risks that often outweigh potential benefits. The medication should be avoided when possible, especially in patients with existing cognitive impairment, fall risk, or urinary retention. If used, it should be prescribed at the lowest effective dose with careful monitoring for adverse effects.