Apex- Pharmacodynamics Flashcards
Pharmacokinetics
What the BODY does to the drug
Pharmacodynamics
What the Drug does to the body
> potency, efficacy, dose-response curve slope, agonist, antagonist, ED50, LD50, Theraputic index, stereochemistry
Chemistry term to describe the drugs specific shape, size, and characteristics which allow it to bind to a certain receptor.
Stereospecificity
A drug that binds to a receptor and fully enhances the response of that receptor
Full agonist
A drug that sit’s on a specific receptor, doesn’t activate it, but blocks an agonist from binding to it.
Antagonist
> it doesn’t tell the cell to do anything
Difference between competitive and non-competitive antagonists
- Competitive = reversible ; wants to compete, can lose and be overridden by increasing concentrations of agonists
* Rocuronium competes with ACH at the NMJ - Noncompetitive = irreversible binding; “not worth my time to even compete with you, I sit and stay, I win, you lose”
* Aspirin inhibits the Cox-1 enzyme fro the entire life of the platelet (7-10days)
If the patient receives a competitive antagonists, will the dose-response curve shift to the right or left?
Right > because it will require MORE of the AGONIST to exert it’s effects
What happens with the dose response curve with noncompetitive agonists?
It shifts down and resembles a partial agonist
What might continuous administration of an agonist cause? Up or down regulation of receptors?
Down regulation - body senses the overstimulation of the target receptors and tries to fix it by not producing as many receptors
Continuous administration of an antagonist may cause up/down regulation of receptors?
Up-regulation. Body senses under stimulation of these receptors and wants to equilibrate by making more receptors
What law describes a drug binding to a receptor?
The law of mass action
Partial agonist AKA: ________
Example
How does it work
Agonist-Antagonist
Ex. Suboxone/ Nalbuphine
Binds to a receptor and PARTIALLY turns it on
>can block the effects of agonist by competing for binding sites
What kind of drug binds to a receptor and directly causes the opposite effect of a full agonist
Example?
Inverse agonist
(Not antagonist bc the antagonists just sit there and don’t cause any effect directly)
Epi- full agonist- binds to B1 > increased cAMP
Propranolol- inverse agonist - binds to B1- decreased levels of cAMP
Chemical term to describe a drug that binds in one place but works somewhere else
Allosteric
Dose- response curve: what represents how many of the receptors must be occupied to exert a clinical effect?
The slope
Dose-response curve- which part represents the ability of the drug itself to elicit a clinical effect? X or Y axis
The Y-axis (vertical)
Which drug is more potent (see dose response curve pic)
Drug A - less dose (x/bottom axis) is required to achieve the same effect of drug B
With a dose-response curve, if the drug has an increased affinity for the receptor, which way will it shift?
To the left
>increased affinity = increased receptors to occupy to elicit the response
See this dose-response curve. If these drugs are narcotics, what assumptions can be made about drugs A and B
Both drugs elicit a response but drug A elicits a greater response (greater analgesia)
Which goes where ? Agonist, Inverse agonist, partial agonist, antagonist
Agonist - binds and enhances normal response
Partial agonist- binds and half ass enhances the normal response
Antagonist - binds to a receptor and prevents binding from other agents
*DOES NOT DIRECTLY EVOKE A CLINICAL RESPONSE!
Inverse agonist- binds to a receptor causing the opposite effect of its normal response
Ex) H1 & H2 blockers
