Pharmacodynamics Flashcards
1
Q
What are some ways drugs can have effects on the body?
A
- Acting on receptors
- Inhibiting carriers (transporters that move 1 or more ions across a membrane)
- Modulating or blocking ion channels
- Upregulating/inhibiting enzymes
2
Q
Describe ligand gated ion channel receptors.
A
- Located on membrane
- Ligand binds to receptor causing ions to pass through channel
- Takes milliseconds to cause response
- EXAMPLE: Nicotinic ACh receptors
3
Q
Describe GPCRs
A
- Located on membrane
- Take seconds to cause a response
- Use an α subunit which activates and inhibits enzymes through biochemical cascades
4
Q
What are the 3 types of GPCRs?
A
- Gαs - activate adenylate cyclase
- Gαq - activate phospholipase C
- Gαi - inhibit adenylate cyclase
5
Q
What is the difference between affinity and potency of a drug?
A
- AFFINITY - How strongly ligand binds to receptor
- POTENCY - Amount of drug required to cause an effect
6
Q
What do the following terms mean
- EC50
- Emax
A
- EC50 - Agonist concentration to elicit a half maximal response
- Emax - Maximal response of drug
7
Q
Outline the difference between a competitive and non-competitive antagonist.
A
- COMPETITIVE - reversible binding to active site of receptor
- NON-COMPETITIVE - binds to allosteric site and prevents receptor activation. Response won’t be maximal
8
Q
What do the following terms mean
- ED50
- TD50
A
- ED50 - Drug concentration to achieve therapeutic effect in 50% of population
- TD50 - Drug concentration to cause toxic effects in 50% of population