CRACKCast E182 – Drug Therapy in the Geriatric Patient

In CRACKCast, Podcast by Chris Lipp2 Comments

This episode of CRACKCast covers Rosen’s chapter 185, Drug Therapy in the Geriatric Patient. Although short, this post contains vital information that will help you optimize the care of yours elderly patients in the ED. Take some time to commit this information to memory, as it will no doubt help you on your next shift.

Shownotes – PDF HERE

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Rosen’s In Perspective

  • The elderly are coming in droves!
  • Drug therapy issues are particularly challenging in older adults because of altered pharmacokinetics and pharmacodynamics compared to younger adults.
  • In addition, they take more medications, have more comorbidities, and are at increased risk for adverse drug effects because of the physiologic changes of aging
    • As a result, medication selection and dosing need to be age-adapted for optimal patient outcomes.

[1] List 4 factors altering pharmacokinetics in the elderly (ADME)

Please refer to Table 185.1 from Rosen’s 9th Edition for a more comprehensive summary of the factors altering pharmacokinetics in the elderly.

Pharmacokinetic Changes in Older Adults

Absorption

  • Increased gastric pH, changing net absorption
  • Delayed gastric emptying, changing net absorption
  • Diminished splanchnic blood flow, delaying peak effects of ingested drugs
  • Diminished bowel motility, altering peak effects of ingested drugs

Distribution

  • Increased adipose tissue, resulting in increased accumulation and duration of effect for lipophilic medications
  • Diminished total body water, resulting in a lower required loading doses for hydrophilic medications

Metabolism

  • Diminished phase one metabolism, resulting in accumulation of phase-1-dependent medications
  • Diminished hepatic blood flow, resulting in altered metabolism

Elimination

  • Diminished glomerular filtration rate, requiring clinicians to make VITAL drug dosage changes; CALCULATE THE CREATININE CLEARANCE in elderly patients regularly

[2] List 6 factors contributing to adverse events from medications in the elderly

  • Polypharmacy / drug interactions
  • Comorbidities
  • All of the pharmacokinetic reasons:
    • Altered GI motility and perfusion
    • Decreased hepatic function
    • Decreased renal function
    • Decreased lean body mass
    • Increased adipose tissue
    • Changes in protein binding

[3] Which meds are most responsible for adverse events in the elderly?

REMEMBER: The Beers criteria are a consensus guideline published semi-regularly that provides clinicians with lists of medications that should be avoided in older adults.

Please refer to Table 185.3 from Rosen’s 9th Edition for a more comprehensive summary of the most common Beers List medications prescribed in the ED.

  1. Promethazine
  2. Diphenydramine
  3. Diazepam
  4. Hydroxyzine
  5. Amitriptyline

[4] List 9 harmful drug interactions in the elderly

Please refer to Table 185.2 from Rosen’s 9th Edition for a more comprehensive summary of harmful drug interactions in older patients

Drug

Adverse Event

ACE Inhibitors/ARB’sHyperkalemia
Benzos and Sedative-HypnoticsFractures, Falls
CCB’sHypotension
DigoxinToxicity
LithiumToxicity
PhenytoinToxicity
SulfonylureasHypoglycemia
TheophyllineToxicity
WarfarinBleeding

[5] What are the top 10 STOPP criteria?

REMEMBER: STOPP (Screening Tool of Older Persons’ Potentially Inappropriate Prescriptions) are newer criteria to identify potentially inappropriate medications in the elderly, including drug–drug and drug–disease interactions, drugs which increase risk the of falls, and drugs which duplicate therapy.

REMEMBER: Unlike the Beers List, the STOPP criteria have been significantly associated with avoidable adverse drug events in older people that cause or contribute to hospitalization.

Please refer to Table 185.4 from Rosen’s 9th Edition for a more comprehensive summary of the top ten STOPP criteria

  1. Long-term use of benzodiazepines
  2. Duplicate prescriptions from the same drug class
  3. Proton pump inhibitor for peptic ulcer disease at full dose for >8 weeks
  4. NSAID’s in patients with moderate to severe hypertension
  5. Long-term use of opioids
  6. Aspirin without adequate cardiovascular risk
  7. Warfarin and NSAID used together
  8. Beta blocker in patients with COPD
  9. Prolonged use of first-generation antihistamines
  10. NSAID use in patients with chronic renal failure
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This post was formatted and copyedited by Dillan Radomske (@dillanradomske)

Chris Lipp

Chris Lipp is one of the founding Fathers for CrackCast. He currently divides his time as an EM Physician in Calgary (SHC/FMC) and in Sports Medicine (Innovative Sport Medicine Calgary). His interests are in paediatrics, endurance sports, exercise as medicine, and wilderness medical education. When he isn’t outdoors with his family, he's brewing a coffee or dreaming up an adventure…..

Adam Thomas

CRACKCast Co-founder and newly minted FRCPC emergency physician from the University of British Columbia. Currently spending his days between a fellowship in critical care and making sure his toddler survives past age 5.