Chapter 8: Individual Variation in Drug Responses

Question 1

Kidney Disease

Answer 1

Reduces excretion

Drug levels can accumulate to toxic levels

Question 2

Liver Disease

Answer 2

Rates of metabolism will decline

Drug levels can accumulate to toxic levels

Question 3

Acid-Base Imbalance

Answer 3

If there is a difference in pH on two sides of a membrane, a drug will accumulate on the side where the pH most favors its ionization.
Because acidic drugs ionize in alkaline media, acidic drugs will accumulate on the alkaline side of the membrane. Conversely, basic drugs will accumulate on the acidic side.

Question 4

Tolerance

Answer 4

Decreased responsiveness to a drug as a result of repeated drug administration.

1) pharmacodynamic tolerance
2) metabolic tolerance
3) tachyphylaxis

Question 5

Pharmacodynamic Tolerance

Answer 5

Familiar type of tolerance. Result of adaptive processes that occur in response to chronic receptor occupation.

Question 6

Metabolic Tolerance

Answer 6

Resulting from accelerated drug metabolism.

Question 7

Tachyphylaxis

Answer 7

Reduction in drug responsiveness brought on by repeated dosing over a short time.

Question 8

Placebo Effect

Answer 8

Component of a drug response that can be attributed to psychologic factors, rather than to direct physiologic or biochemical actions of the drug. Solid proof that most placebo effects are real is lacking.

Question 9

Bioavailability

Answer 9

The amount of active drug that reaches the systemic circulation from its site of administration.
Differences in bioavailability matter most for drugs that have a narrow therapeutic range.

Question 10

Pharmacogenomics

Answer 10

The study of how genetic variations can affect individual responses to drugs.

Question 11

Genetic variations

Answer 11

Genetic variations can alter the structure of drug receptors and other target molecules, and can thereby influence drug responses.
Genetic variations that alter immune reactions to drugs can result in severe injury, and even death.

Question 12

Factors that influence response

Answer 12

Dosages may be adjusted based on SURFACE AREA to account for fat content
Infants sensitive due to immaturity of organs
In elderly, sensitivity is due to organ degeneration
Starvation = low serum albumin = less protein bound drug = more free drug