LG 6.9 - Pharmacodynamics Pt. 1 Flashcards
1
Q
What are common biologic targets for drugs?
A
- Receptors.
2
Q
What do receptors do regarding the drugs?
A
- Quantitative interactions between dose or concentration and pharmacological effects.
- Responsible for selectivity of drug action.
- Mediate the actions of pharmacological agents.
3
Q
What is an agonist?
What is an antagonist?
A
- Agonist drugs activate the receptor that directly or indirectly brings about an effect.
- Antagonist bind to the receptor compete with and prevent binding by other molecules.
4
Q
What is the difference between a competitive antagonist and a noncompetitive?
A
- Competitive: Binds to active site and prevents agonist from binding.
- Non-competitive: bind to an active site or allosteric site (other site) than the active site.
5
Q
What happens when antagonist binds active site vs. non-active site?
A
- Binds active with covalent high affinity bond (irreversible).
- Binds allosteric site prevents receptor activation by agonist (effectively irreversible).
6
Q
What is chemical antagonism vs. physiological antagonism?
A
- Chemical: two drugs combine and the activity neutralized.
- Physiological: when a receptor is activated facilitates a effect is opposite of the agonist.
7
Q
What are some variations in drug response?
A
- Tolerance
- Desensitization
- Refractory
- Down regulation
8
Q
What is tolerance?
A
- Occurs when responsiveness decreases as a consequence of continued drug administration.
9
Q
What is desensitization? Two types?
A
- When receptors and cell response diminishes by a drug or ligand.
- Homologous: decreased response at single type of receptor.
- Heterologous: decreased response at two or more types of receptors.
10
Q
What is refractory?
A
- When time is required to pass before receptor can be stimulated again.
11
Q
What is down-regulation?
A
- Prolonged stimulation leads to endocytosis and sequestration of receptors.
- Receptors can be recycled to cell surface, degradation.
