WEEK 8 Flashcards
Variability in response to a drug can be categorised as being … or … in nature.
pharmacokinetic or
pharmacodynamic
During metabolism, a drug
is usually converted into a more …-soluble compound.
water-soluble compound.
T or F
People can differ in the
ratio of different metabolites that they produce.
T
Frequently, a drug
simultaneously undergoes metabolism by several competing … pathways.
Enzyme
T or F
Drug excretion does not vary across people and within an individual over time.
F
It does vary.
T or F
Normally only free or unbound drug can interact with drug target sites.
T
T or F
A drug’s effect at its site of action can vary across people and within an individual over time.
T
T or F
Most drugs work by interacting with receptors, enzymes or other
exogenous proteins within the body.
F
Endogenous
In terms of pharmacokinetic processes – variability in drug response may be
due to variability in drug …, …, … or …
absorption, distribution, metabolism or excretion.
As a result of pharmacokinetic variability people taking the same dose of a
drug can have different … of drug in their body over time,
leading to different drug responses.
concentrations
Variability in drug response can be due to differences in….
across people and within an individual over time.
receptor and enzyme expression, receptor or enzyme
affinity for the drug and the post-target transduction
process
As a result of pharmacodynamic variability people with the same drug exposure can have different drug …
responses
What is “inter-subject
variability”?
Variability in drug response may be between individuals
What is “intra-subject variability”?
Variability within a person over time
T or F
Inter-subject variability is generally much smaller than intra-subject variability.
F
Intra-subject variability is generally much smaller than inter-subject
variability.
As a result of variability, the dosage regimen of some drugs may need to be individualised to patients’ needs by dose titration based on … or …
Dose titration based on a person’s response to the drug
or
Dose titration based on drug concentrations (TDM)
Dose titration based on drug concentrations is called what?
TDM
Dose titration based on drug concentrations is used if…
If a relationship between drug concentration and effect exists and effect is difficult to measure.
The potential need for individualised therapy is greatest for drugs that have a
… therapeutic index.
narrow
What does it mean when a drug has a narrow therapeutic index?
Drugs with a narrow therapeutic index are those where there is little difference between a therapeutic dose of the drug and a dose that causes significant toxicity.
What are some examples of drugs with a narrow therapeutic index?
Examples of such drugs include digoxin, theophylline, warfarin, lithium carbonate, gentamicin, vancomycin, phenytoin, cyclosporine, tacrolimus and many
anti-cancer drugs.
For a drug with a narrow therapeutic index there is little difference between
the drug dose required for … and the drug dose that can lead to significant …
efficacy
toxicity
Some major sources of pharmacokinetic variability include the following factors…
Genetics
Age
Gender
Weight
Hepatic disease
Renal disease
Cardiovascular disease
Drug interactions
Environmental influences
T or F
Drug metabolic enzymes, transporters and target proteins can all vary in activity and expression across individuals.
T
