Drug Variability

Question 1

Why does variability in drug response matter

Answer 1

in drug formation, the goal is that the drug will have an optimal response, however most drugs will only be effective in 25%-60% patients.

They have to figure out what standard drug dosage regimens that will have the optimal response to most patients

Question 2

What factors affect drug response variability?

Answer 2

compliance
bioavailability
pharmacokinetic variation
pharmacodynamic variation

Question 3

what effects patient compliance

Answer 3

patient related factors
disease related factors
treatment related factors

Question 4

Choose 1: which of the following does not influence patient compliance?

A. demographic factors
B. Age
C. seriousness of compliance
D. A and C
E. A,B,C

Answer 4

E

Question 5

what patient related factors affect compliance

Answer 5

psychological factors
social isolation
perception of illness
cognitive impairment

Question 6

disease related factors affect compliance

Answer 6

patient’s perception of the seriousness of the illness
some disorders like schizophrenia might also impact a patient’s ability to take their psychotic pills

Question 7

Treatment-Related Factors

Answer 7

complexity of dosing regimen inversely proportional to compliance
unwanted affects of drug
packaging and potability

Question 8

how does bioavailability influence variability

Answer 8

how much of the drug is absorbed and how much reaches its target site will vary based on an individual’s set of factors

Question 9

pharmacokinetic variation

Answer 9

age
body composition
induction/inhibition

Question 10

how does body composition influence dosing

Answer 10

variability in volume of distribution between individuals is due to body composition

Question 11

will an obese individual of the same weight asa a more lean individual require higher/lower dose of water soluble/lipid soluble drug

Answer 11

an obese individual requires a higher does of a lipid soluble drug and a lower dose of water soluble drug

Question 12

how does meningitis contribute to variability

Answer 12

The information of meningitis will increase permeability of the BBB however if you increase the dose of antibiotics you will raise the risk of seizures

Question 13

will liver disease/dysfunction alter variability

Answer 13

yes it can alter the metabolism of the drug

Question 14

what will a fever affect in relation to drug variability

Answer 14

it will change plasma protein binding and further Volume of distribution

Question 15

T/F. pharmacogenetic variation in enzyme activity does not effect pro-drug activation and half life, but it does effect drug elimination

Answer 15

FALSE. pharmacoogentic variation affects all of these things

Question 16

Describe how terfenadine is an example of drug-drug interactions impacting variability

Answer 16

seldane, an allergy medication prevents CYP3A and increased terfenadine which is associated with arrhythmia

Question 17

how is the Vd of drug impacted by age

Answer 17

for children their TBW is higher so they will be able to have a higher Vd of hydrophilic drugs and hence, lower plasma protein binding

for older people they have more fat and higher VD of lipophilic drugs

Question 18

pharmacodynamic variation

Answer 18

differences in receptor density, affinity, signalling

differences in formation and elimination of endogenous ligands

Question 19

polymorphism

Answer 19

variability in the enzyme’s ability to metabolize drug. some people can have a higher metabolism than others