Geriatric Toxicology

Introduction

• Limited physiological reserve
• Deteriorating cognition
• Multiple comorbidities
• Multiple prescribed medications
• Result in exaggerated and unpredictable responses to any toxicological insult
• Predict more severe clinical course for given dose
• Age is highly correlated to case fatality rate and each 10 year increase in age is associated with 36% increase in the odds ratio for death following poisoning
• More likely to require hospital level care after accidental exposures and adverse drug effects

Pharmacokinetic changes

• Delayed GI absorption
• Decreased protein binding
  • Increased free drug levels
• Reduced hepatic metabolism
  • Prolonged half-life
• Reduced GFR
  • Impaired elimination
• Acute kidney injury due to intercurrent medical problems or prescribed medications often leads to poisoning syndromes as in chronic lithium or digoxin toxicity

Pharmacodynamic differences

• Physiologically impaired end organs
• CVS, respiratory and CNS specifically
• Clinical assessment of volume status is often unreliable and a lower threshold for invasive monitoring is required

Disposition

• Elderly patients will have a delayed recovery
• Complications of immobility and hospital admission are seen more frequently in the elderly
  • Atelectasis
  • Pneumonia
  • PE
  • Catheter-induced sepsis
  • Muscle wasting
  • Delirium

Last Updated on October 14, 2020 by Andrew Crofton