Effects of aging

 

Effects of aging

Drug-receptor interaction

  • Brain receptors become more sensitive, making psychoactive drugs very potent.

Metabolism

  • Liver mass shrinks.
  • Hepatic blood flow and enzyme activity decline.
  • Metabolism drops to 1/2 to 2/3 the rate of young adults.
  • Enzymes lose ability to process some drugs, thus prolonging drug half-life.

Absorption

  • Gastric emptying rate and gastrointestinal motility slow.
  • Absorption capacity of cells and active transport mechanism decline

Circulation

  • Vascular nerve control is less stable.
  • Anti-hypertensives, for example, may overshoot, dropping BP too low.
  • Digoxin, for example, may slow the heart rate too much.

Excretion

  • In kidneys, renal blood flow, glomerular filtration rate, renal tubular secretion and reabsorption, and number of functional nephrons decline.
  • Age-related changes increase half-life for renally excreted drugs.
  • Oral antidiabetic drugs, among others, stay in the body longer.

Distribution

  • Lean body mass falls.
  • Adipose stores increase.
  • Total body water declines, raising the concentration of water-soluble drugs, such as digoxin, which can cause heart dysfunction.
  • Plasma protein levels decrease, reducing sites available for protein-bound drugs and raising blood levels of free drug.
    • Safety
      • Older adults are at higher risk for accidents
        • Most occur in or around the home
      • Declining thermoregulation accounts for the higher rate of deaths during severe cold spells and heat waves
      • Carefully orient older adults on admission
    • Depression
      • Not a normal part of aging
      • Second highest rate of suicide occurs in those over 75
      • Occurs together with medical conditions
    • Adequacy of sleep is a common concern
  • Evaluation
    • Is there an identifiable change in ADLs, IADLs, mental status, or signs and symptoms of the disease?
    • Does the individual consider his or her health state to be improved?
    • Does the individual think the plan is helpful?
    • Do the individual and caregiver think the care is worth the time and cost?
    • Can you document positive changes that support the interventions?

Share:

More Posts

Cerebral Aneurysms

ON THIS PAGE What is a cerebral aneurysm? Who is more likely to get a cerebral aneurysm? How are cerebral aneurysms diagnosed and treated? What

Learn How To Control Asthma

On This Page What is Asthma? How Can You Tell if You Have Asthma? What Is an Asthma Attack? What Causes an Asthma Attack? How