lecture 14

Question 1

What are the two questions that are important for every drug that can be answered by a time-action curve?

Answer 1

how quickly will the drug act?
how long will the drug effect last?

Question 2

Even after the primary effects are terminated, it is possible for a drug to exert a _________ that is unmasked when another dose of the same drug is given.

Answer 2

residual effect

Question 3

Residual effect may also occur when _______ is given and the phenomenon of antagonism or potentiation is manifested.

Answer 3

another entirely different drug

Question 4

_________ assumes that at the dose given, the subject will respond to the maximum or not at all, and the response of an individual subject is binary.

Answer 4

quantal log-dose response (all or none) relationships

Question 5

_____ is the dose required to produce the stated effect in 50% of the population

Answer 5

median effective dose (ED50)

Question 6

______ is the dose required to produce death in 50% of the population or a particular toxic effect in 50% of the population.

Answer 6

medial lethal dose (LD50) or median toxic dose (TD50)

Question 7

The therapeutic index is expressed as ______.

Answer 7

LD50/ED50 or TD50/ED50

Question 8

The larger the ratio for the therapeutic index, the ______ the relative safety

Answer 8

greater

Question 9

The ______ system is capable of showing progressively increasing effects with increasing concentrations of the drug.

Answer 9

graded log-dose response (not all or none)

Question 10

The log-dose response curve is _____, the midpoint represents the dose at which 50% ______ is elicited, and allows comparison of drugs with similar properties.

Answer 10

sigmoidal
maximum response

Question 11

Which is not a graded response?
A. Blood sugar lowering effect of insulin
B. Blood pressure controlled by propanolol
C. Prevention of anaphylaxis reaction to penicillin by norepinephrine
D. Dilation of eye pupils by atropine
E. All of the above

Answer 11

C
you are either in anaphylaxis or not

Question 12

Glucagon, a hormone, also known as the physiologic antagonist of insulin, is used in life threatening situations of hyperinsulinemia. A pharmaceutical company is doing research to develop an appropriate analogue of glucagon for emergency situations like this. Which attribute do you think should be considered most for a potential analogue?
A. Onset of action
B. Duration of action
C. Peak effect
D. Therapeutic window

Answer 12

A and D both correct

Question 13

____ is a condition of decreased responsiveness to a drug, acquired after prior or repeated exposure to a given drug or a closely related one.

Answer 13

drug tolerance

Question 14

If tolerance has developed, it is necessary to ______ the dose to produce the effects of equal magnitude or duration.

Answer 14

increase

Question 15

Development of drug tolerance can occur from a decrease in _______ of the agonist at the site of action, increased enzyme activity and decreased effect of drug.

Answer 15

effective concentration

Question 16

Development of drug tolerance can also result from a decrease in the _____ of the receptor, down-regulation of receptors, and change in receptor affinity.

Answer 16

normal reactivity

Question 17

_______ is when tolerance develops to one drug that is also seen with drugs belonging to the same class (ex: tolerance to morphine may also cause tolerance to other opioids).

Answer 17

cross tolerance

Question 18

_______ is the acute development of tolerance following rapid and/or repeated administration of a drug. The first administration of drug produces a much larger response than subsequent doses and increasing the dose does not overcome tolerance.

Answer 18

tachyphylaxis

Question 19

_______ is a genetically-determined abnormal reactivity to a drug, may be extreme sensitivity to low doses or insensitivity to high doses, often a difference in drug metabolizing enzymes.

Answer 19

idiosyncratic reaction

Question 20

How might age modify the effects of drugs?

Answer 20

neonates/children/geriatric patients have either underdeveloped or diminished activity of hepatic and renal clearance ability and are often given a fraction of the adult dose

Question 21

How might sex modify the effects of drugs?

Answer 21

males and females respond differently sometimes to some medications due to different levels of sex hormones, body fat, liver activity and other factors

Question 22

How might pregnancy modify the effects of drugs?

Answer 22

drug disposition is altered during pregnancy and metabolic and cardiac output is increased and GFR is elevated

Question 23

How might food modify the effects of drugs?

Answer 23

to prevent gastric irritation, drugs are taken after or between meals, which impacts the absorption rate

Question 24

How might the circadian clock modify the effects of drugs?

Answer 24

endogenous body cycle might affect drug responses in some cases

Question 25

How might liver disease modify the effects of drugs?

Answer 25

liver disease affects the blood flow and function of hepatocytes, which have a prominent role in drug metabolism, possibly leading to prolonged half life

Question 26

How might renal disease modify the effects of drugs?

Answer 26

reduced kidney function impairs the ability to retain/excrete the drugs and their byproducts through glomerular function

Question 27

How might malnutrition modify the effects of drug function?

Answer 27

plasma protein binding of drugs reduces significantly under malnutrition

Question 28

How might pseudocholinesterace deficiency modify the effects of drugs?

Answer 28

it can by caused by mutations in the BCHE gene and results in increased sensitivity to certain muscle relaxant drugs used during general anesthesia, called choline esters

Question 29

How might malignant hypothermia modify the effects of drugs?

Answer 29

variations of the CACNA1S and RYR1 genes are the primary cause of developing malignant hypothermia.

Question 30

How might oxidation polymorphism modify drug effects?

Answer 30

extensive metabolizers need larger doses, while poor metabolizers need smaller doses

Question 31

How might pharmacokinetics modify the effects of drugs?

Answer 31

a majority of drugs are metabolized in the liver by CYP enzymes. Multiple drugs can be metabolized by the same enzyme, and administering drugs together might lead to rapid clearance of one another

Question 32

How might pharmacodynamics modify the effects of drugs?

Answer 32

pharmacodynamic drug interactions occur when drugs act at the same or interrelated receptor sites, resulting in additive, synergistic, or antagonistic effects of each drug.

Question 33

A _____ is a formulation that is identical in appearance to the real product but without the active drug.

Answer 33

placebo

Question 34

What are some additional factors in drug responses?

Answer 34

endogenous ligand concentration alteration in receptor number changes in post-receptor signaling receptor mutations diet, environment, antibiotic resistance, etc