Dose-Response Relationship

Question 1

Describe: Graded Dose Response Curve

Answer 1

response depicts the effect of varying doses of a drug on an individual in which the response is a continuous variable

Question 2

Describe: Tail Flick Test

Answer 2

rat is placed on a platform with a heat source near it’s tail. the rat is given increasing doses of morphine and the time to tail flick is recorded. as the rat is given more morphine, the longer it leaves it’s tail near the heat source.

Question 3

How is drug response distributed in the population?

Answer 3

Gaussian (normal distribution)

Question 4

What information can be obtained from a normal distribution drug response curve?

Answer 4

x-axis: concentration of drug (log curve), y-axis: % of subjects with response, ED50: median effective dose at which 50% of subjects having the significance response

Question 5

What information can be obtained from a quantal dose- response curve?

Answer 5

3 curves (therapeutic effect, toxic effect, lethal effect), ED50= median effective dose, the dose at which 50% of subjects demonstrate therapeutic effect, TD50= median toxic dose, LD50= median lethal effect

Question 6

Define: Therapeutic Index

Answer 6

= LD50/ED50 or = TD50/ED50, higher the value the safer the drug

Question 7

Define: Therapeutic window

Answer 7

range of drug concentration that provides therapeutic effects, but with minimal toxic effects

Question 8

Define: Certain Safety Factor

Answer 8

LD1/ED99

Question 9

Define: Pharmacokinetics

Answer 9

dose administered versus drug concentration in the body

Question 10

Define: Pharmacodynamics

Answer 10

drug concentration versus pharmacological effect

Question 11

Define: Absorption

Answer 11

process of getting drug from site of administration into the blood stream

Question 12

Define: Distribution

Answer 12

post-absorption disposition of drug, where it goes after getting into blood stream

Question 13

Define: Metabolism

Answer 13

body converts the drug into a different compound, usually to terminate drug action by converting into a water-soluble compound. liver is the major organ responsible for this

Question 14

Define: Excretion

Answer 14

removing the drug (either parent drug or metabolite) from the blood stream to outside the body. could be eliminated in urine, bile, sweat, respiration. water soluble compounds are more easily excreted by the kidneys

Question 15

What routes of administration are NOT subject to first pass metabolism?

Answer 15

-parenteral
-mucous membrane
-transdermal

Question 16

Describe: IV drug administration

Answer 16

-rapid onset
-rapidly distributed= steep decline in plasma drug concentration
-drug concentration decreases slowly= elimination phase

Question 17

What drug routes are subject to the “first-pass effect”?

Answer 17

oral

Question 18

Define: Bioavailability

Answer 18

quantity of drug reaching systemic circulation/quantity of drug administration