Pharm Unit 1 Flashcards
pharmacologic effect
visible response to a drug
pharmacokinetics
branch of pharmacology concerned with movements of the drug within the body and its excretion
pharmacodynamics
Ability of drug to produce an effect and it’s mechanism of action
Emax
Maximum response of a drug
related o the number of drug receptor interactions and the physiologic capacity of the tissue
Reversible drug bond types
Ionic, Van der Waals, Hydrogen
Irreversible drug bond
Covalent
G protein subunit Alpha s
increases adenylyl cyclase, & increases Ca current
G protein subunit Alpha i
Decreases adenyyl cyclase, & increases K current
G protein subunit Alpha o
decreases Ca current
G protein subunit alpha q
increases phospholipase Cbeta
G protein subunit alpha 13
increases Na/H exchange
G protein subunit alpha 1
increases cGMP-phosphodiesterase (vision)
G protein subunit alpha olf
increases adenylyl cyclase (olfaction)
EC50
the quantity of the drug that produces 50% of the maximal response
x-axis: log[drug concentration]
y-axis: response
Threshold
dose of agonist at which a response begins
Maximal Asymptote
top of the curve, represents Emax
Intrinsic Activity
Ability to stimulate the receptor once bound
If two agonists have different intrinsic activities they will different Emaxs
Michaelis-Menten equation
Effect=(Emax[D])/(Kd+ [D])
Kd=dissociation constant=EC50
Hypersensitivity
Occurs with Antagonist drugs, once pt stops taking the drug they have a greater than normal response to the endogenous level of the substance that was being blocked.
Desensitization
Occurs with Agonist Drugs
there can be down regulation of the receptor or fatigue with the depletion of the intracellular or tissue mechanisms
Affinity
The higher the affinity the lower the EC50
Efficacy
The ability of the drug to activate the effector portion of the receptor once the drug is bound to the receptor
Depends on: the structure of the drug
Potency
Relates to the amount of drug needed for an effect
Depends on:
1)Receptor density
2)efficiency of the stimulus response mechanisms of the tissue
3)the affinity and efficacy of the drug
pKa
determines ratio of ionized to nonionized drugs at a particular pH