14. PHARMACODYNAMICS Flashcards
(38 cards)
Define “pharmacoDynamics”
The effect the DRUG has on the BODY
List variables that are associated with “exposure”
Css, Cmax/min, AUC
Define “exposure”
ANY dose or drug impact to the body OR various measures of drug concentration in biological fluid (ie. plasma)
Define “response”
Direct measure of a pharmacologic observation at a point in time
List variables that are associated with “response”
Rmax
Biomarkers
Clinical / harmful response
What pharmacologic terms are often used interchangeably?
Response & Effect
Define “effect”
Change in biological response from one time point to another
Why might there be a delayed response to a drug?
- Upregulation of receptor of administration
- Second messengers
- Secondary action / effect
- Prodrugs, production of an active metabolite that produces a response
- Production of an active metabolite that produces a response similar to the parent drug
- Delay in drug reaching the site of action
Give an example of a drug that has a delayed effect due to a delay in reaching the site of action
Digoxin reaching the heart to produce an effect
Give an example of a drug that has a delayed effect due to the production of an active metabolite that produces a response similar to the parent drug
Morphine → glucuronide can cause prolonged analgesic effects
Give an example of a drug that has a delayed effect due to up-regulation of a receptor or sensitization
Beta-blockers when administered long-term
Give an example of a drug that has a delayed effect due to the response being a secondary effect
Corticosteroids require protein synthesis to produce their therapeutic effect
What is true about Rmax and Emax for a drug that produces a delayed effect?
Rmax appears after Emax is reached
What does a counterclockwise hysteresis loop indicate?
A drug with a delayed response
What is a clockwise hysteresis loop also known as?
A proteresis loop
What does a proteresis loop indicate?
A decrease in effect over time
Tolerance
What direction is a proteresis loop?
Clockwise
List potential reasons for a proteresis loop
- Desensitization
- Production of an active metabolite that produces the OPPOSITE effect as the parent
Users of long-term opioid analgesics can experience tolerance to the drug over time. How would this concentration / effect relationship be represented graphically?
As a clockwise loop / proteresis loop
Would the following relationship be an example of pharmacokinetics or pharmacodynamics?
“As k increases, CL also increases”
Pharmacokinetic, it describes excretion, or, “what the BODY does to the DRUG”
ADME is a pharmacokinetic descriptor
Describe the relationship between pharmacokinetics and pharmacokinetics
Pharmacokinetics determines CONCENTRATION (conc v time), pharmacodynamics translates PK into a RESPONSE (response v conc)
When PD and PK are put together, effect over time can be predicted
Which graph represents pharmacokinetics?
concentration vs. time
effect vs. concentration
effect vs. time
concentration vs. time
Which graph represents pharmacodynamics?
concentration vs. time
effect vs. concentration
effect vs. time
effect vs. concentration
What types of response vs. concentration relationship can be obtained by measuring the experience of ONE person?
Graded
