Geriatics

Question 1

What are the 3 changes to the stomach in geriatrics?

Answer 1

• decreased secretion of HCl and pepsin (basal conditions)
• atrophy of gastric mucosa
• gastric emptying similar to that of young subjects

Question 2

What are the 4 changes to the small intestine in geriatrics?

Answer 2

• reduced absorption of several substances (e.g. sugar, Ca, Fe)
• digestion and motility remain relatively unchanged
• atrophy of intestinal macro-and micro-villi
• possible bacterial overgrowth in intestine

Question 3

What are the 6 physiological cardiac changes in geriatrics?

Answer 3

• Decreased cardiac output and stroke volume
• Lengthening of recovery time after exercise
• Increase in blood pressure
• Increased peripheral vascular resistance
• Greater rise in systolic than diastolic blood pressure
• Increased circulation transit time

Question 4

What are the 3 anatomical changes of the heart in geriatrics?

Answer 4

• Endocardial thickening
• Increase in collagen
• Increase in elastic fibers

Question 5

What are the 3 changes to the liver in geriatrics?

Answer 5

• progressive reduction in liver volume and liver blood flow
• moderate alteration of hepatic structure and enzymatic functions
• increase in the size of hepatocytes

Question 6

What are the 3 changes to the pancreas in geriatrics?

Answer 6

• amylase remain constant
• lipase, trypsin decrease dramatically
• secretin-stimulated pancreatic juice and bicarbonate concentrations remain unchanged

Question 7

What are the 5 changes to the renal system in geriatrics?

Answer 7

• Decreased renal blood flow, glomerular filtration rate and tubular secretion
• Decreased renal mass (reduced nephrons)
• Plasma creatinine: no concomitant increase (age-related loss of muscle mass); not a reliable indicator of glomerular filtration rate
• Acid-base balance maintained
• Reduced response to stress: inability to deal with acid loads

Question 8

What are the 5 examples of pk (absorption) altered in geriatrics?

Answer 8

• Reduced absorption of vitamin B12, iron and calcium due to active transport mechanisms
• Increased absorption of Levodopa
• Decreased BA of Digoxin
• Higher extent of absorption of clomethiazone, cimetidine, propranolol
• Reduced rate of absorption of quinidine, chlordiazepoxide

Question 9

What are the 3 pk implications to first pass-metabolism and bioavailability in geriatrics?

Answer 9

• Reduction in first-pass metabolism
• Increased BA of drugs undergoing extensive first-pass metabolism (propranolol and labetalol)
• Decreased BA of prodrugs that need to be activated in the liver (enalapril and perindopril)

Question 10

What are the 2 pk implications to distribution in geriatrics?

Answer 10

• Polar compounds (water soluble): smaller Vd (higher serum levels); little net effect on the elimination half life (gentamicin, digoxin, ethanol, theophylline, and cimetidine).
• Nonpolar compounds (lipid soluble): increased Vd; prolongation of half-life (diazepam, thiopentone, lignocaine, and chlormethiazole).

Question 11

What are the 2 pk implications to renal clearance in geriatrics?

Answer 11

• Reduction in renal function
• Drugs with a narrow therapeutic indexare likely to cause serious adverse effects (accumulation)

Question 12

What are the 2 pk implications to hepatic clearance in geriatrics?

Answer 12

• Reduction in liver blood flow: affect the clearance of drugs with a high extraction ratio.
• Enzyme inhibition, pathways of conjugation: no major effects of ageing