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Dose Response
site of drug action, dose response and agonist/antagonists
How do you classify a drug? | It is an agent that interacts with specific target molecules in the body and produces a physiological effect |
Pharmacodynamics means: | The mechanism by which drugs exert their effect on the body for a therapeutic action to occur. Includes drug-receptor interactions |
Pharmacokinetics is: | what the body does to the drug i.e. absorption, metabolism and excretion |
The three main aspects of NON-POTENT drugs are: | 1) active at high concentrations 2) little structural specificity 3) cause physical change |
The three main aspects of POTENT drugs are: | 1) act at low concentrations 2) structural specificity 3) act by chemical interactinon |
Receptors are the site at which a ligand attached. They may be: | Neurotransmitters, hormones or local factors. Activation of a receptor by these produces a response |
with increased concentration of a drug, there is: | increased risk of non-specific side effects |
Agonists: | mimic endogenous ligands, binding to a receptor and causing an effect |
Antagonists: | bind to a receptor and prevent the action of an agonist. Most are competitive and reersible |
Drug-Receptor interaction assumes that: | the effect of a drug is proportional to the fraction of receptors occupied |
Efficacy is: | the measure of a drug's effectiveness to produce a maximal result |
Affinity: | Binding of a drug to a receptor |
Efficacy: | Response to binding |
ED50 (EC50): | 50% of maximal effect |
Competitive (surmountable) Antagonism: | most common in therapeutic drugs. Maximal effect unchanged. agonist and antagonist compete at high affinity for receptor sites parallel shift to the right |
Non-Competitive (Irreversible) Antagonism: | receptor must die for effect to stop. act on receptor itself so that agonist can not bind. Max effect no longer produced |
Spare receptors |