General Principles of Drug Action Flashcards
What is a drug?
Chemical substance of known structure, other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect.
What is the meaning of pharmacodynamics?
The effect of a drug on the body.
What is the meaning of pharmacokinetics?
The effect of the body on the drug.
What are the main targets for drug action?
- Receptors
- Ion Channels
- Enzymes
- Carrier molecules / transporters
Why is it important for a drug to have high specificity for a target?
This reduces the incidence of side effects.
What is an agonist?
Substance which binds to a receptor and causes a direct biological response.
What is an antagonist?
Substance which binds to a receptor but does not cause a response.
What does affinity mean?
How avidly a drug binds to its target site.
What does efficacy mean?
The drug’s ability to activate the receptor once it has bound to it.
What does the law of mass action state?
Rate of chemical reaction is proportional to the product of the concentrations of the reactants.
What are the two scales used to depict affinity?
Linear Scale
Log Scale
How can the relation between drug concentration and effect be tested?
This can be stupid by using a relevant bioassay (IE: An organ bath).
What is Emax?
The maximal response created by a drug.
Emax is a measure of efficacy.
What is EC50?
50% of the maximal response created by s drug.
EC50 is a measure of potency.
What is potency?
The amount required to produce an effect.
Is a measure of drug activity.
