Pharmacodynamics

Question 1

define pharmacodynamics

Answer 1

1 of the 3 types of drug interaction

describes ANY effect the drug has on the human body (intended or not)

Question 2

what are the types of pharmacodynamic interaction? how many types are there

Answer 2

3 1/2 types

1. additive/summation drug interactions
2. synergy
3. antagonism
4. potentiation (argument about whether this should be counted)

Question 3

what is summation/additivity?

give the mathematical representation

Answer 3

type of pharmacodynamic drug interaction

when the effect of two drugs given in combination equals the mathematical summation of their effects when given alone.

1+1=2

Question 4

what is synergy?

give the mathematical representation

Answer 4

type of pharmacodynamic drug interaction

when the combined effect of two drugs is greater than the sum of their effects when given separately

1+1 > 2

Question 5

given an example of 2 drugs that interact in a synergetic manner

Answer 5

morphine and paracetamtol

combined they have a greater effect then the sum of their individual affects

Question 6

what is antagonism ?

give the mathematical representation

Answer 6

type of pharmacodynamic drug interaction

an antagonist is a substance that acts against and blocks an action (2 drugs opposed to each other)

1+1=0

Question 7

what is potentiation ?

give the mathematical representation

Answer 7

type of pharmacodynamic drug interaction ( is debatable if it fits in this category)

enhancement of one drug by another so that the combined effect is greater than the sum of each one alone

1+1=1+1.5

One of the drugs is unaffected, one is enhanced. creates this greater effect

Question 8

what are drug interactions to be aware of?

Answer 8

grapefruit juice

warfarin