Pharmacology Chapter 8 - Individual Variation in Drug Responses

Question 1

Factors that influence drug responses are…(4)

Answer 1

Body weight and composition, age, gender, and pathophysiology.

Question 2

Body weight and composition - more info

Answer 2

drug achieves a higher concentration in smaller people given the same dosage.

Question 3

Age - more info

Answer 3

infants are very sensitive to drugs, and elderly are very sensitive to drugs due to organ degeneration.

Question 4

Gender - more info

Answer 4

response is different to same drug and dosage between men and women.

Question 5

Pathophysiology - drug

Answer 5

how disease affects responses to drugs.

Question 6

Four pathological conditions -

Answer 6

Kidney, Liver, Acid-Base Imbalance, Electrolyte Imbalance.

Question 7

Kidney (PC) -

Answer 7

reduce drug excretion

Question 8

Liver (PC) -

Answer 8

site of drug detoxification and metabolism

Question 9

Acid-Base imbalance (PC) -

Answer 9

alters absorption, distribution, metabolism, excretion. Drug will accumulate on the side of the membrane where pH favors ionization of drug. Acid/Acid - Base/Base

Question 10

Altered Electrolyte Imbalance - PC

Answer 10

Electrolytes (K, Na, Ca, MG) are important in cell physiology and function.

Question 11

Drug tolerance - def

Answer 11

decreased responsiveness to a drug due to repeated drug administration.

Question 12

Drug tolerant patients require ___ doses to produce the same effects that could be achieved with lower doses.

Answer 12

Higher.

Question 13

Three Categories of Drug Tolerance -

Answer 13

Pharmacodynamic, Metabolic, and Tachyphylaxis (less response after repeated applications.)

Question 14

Pharmacodynamic Tolerance -

Answer 14

associated with long-term administration of drugs (such as heroine). patient requires increased doses to produce effects.

Question 15

Metabolic Tolerance -

Answer 15

tolerance due to accelerated drug metabolism. Induced by synthesis of increased levels of liver enzymes (Barbituates). Increase in dosage of drug to maintain level of drug in blood that is equal to previous non tolerant levels.

Question 16

Tachyphylaxis - def and why?

Answer 16

form of tolerance defined as a reduction in drug responsiveness brought on by repeated dosing over a short time. Rare. From depletion of co-factor, like from a patch that was left on constantly, instead of intermittently.

Question 17

Placebo effect -

Answer 17

preparation that has no therapeutic effect.

Question 18

Genetics - idiosyncratic effects

Answer 18

Mostly through rate of metabolism of drug (or due to differences in enzyme levels in organs.)

Question 19

Idiosyncratic effect - def -

Answer 19

uncommon drug response resulting from a genetic predisposition.

Question 20

Bio availability - def

Answer 20

ability of a drug to reach the systemic circulation from its site of administration.

Question 21

Patient Compliance - def

Answer 21

cooperative and accurate participation in one’s drug therapy.