Author Question: An older adult is receiving the highly protein-bound drug phenytoin (Dilantin). Compare the ... (Read 127 times)

audragclark · **on:** Jul 23, 2018

An older adult is receiving the highly protein-bound drug phenytoin (Dilantin). Compare the fol-lowing effects and choose the one that describes changes this drug will undergo owing to the effects of aging on blood components.

a. Greater biotransformation, making smaller amounts of the drug necessary
b. Greater biotransformation, making greater amounts of the drug necessary
c. Less biotransformation, making smaller amounts of the drug necessary
d. Less biotransformation, making greater amounts of the drug necessary

Question 2

Which of the following factors will enhance drug absorption from the older adult's gastrointesti-nal (GI) tract?

a. Physical activity
b. Dehydration
c. Hypothermia
d. Hypotension

cascooper22 · **Reply #1 on:** Jul 23, 2018

Answer to Question 1

ANS: B
Drug distribution and equilibration rates are affected by changes of aging that alter protein bind-ing, volume of distribution, amount of body fat present, and regional perfusion patterns. Re-duced plasma protein levels can result in higher concentrations of unbound drug, especially when the drug competes with other protein-bound drugs. As a result, more unbound drug circulates, increasing the action of highly protein-bound drugs, but this effect is not always predictable.

Answer to Question 2

ANS: A
Blood flow to the GI tract may be altered to maintain coronary and cerebral blood flow. The re-sult is delayed, less thorough absorption, and less-reliable removal of drugs and other substances from the intestinal lumen. In turn, however, exercise stimulates circulation and increases drug absorption.