Essential Pharmacolgy 2 Flashcards
What is a drug?
Any chemical agent that affects a biological system
What are sources of drugs?
- Natural products
- Synthetic drugs generate by pharmaceutical industry
- Biotechnology using living systems to make therapeutic agents
- Gene therapy to introduce new DNA
How do drugs act?
By interacting with a binding site/receptor
What are some examples of receptors?
- Cell surface receptor
- Intracellular receptors
- Ion channels
- Carriers
- Enzymes
- Nucleic acids
How do you get a bigger response?
Increasing the amount of drug
What happens once you reach saturation level for receptors?
There will be no further change in size of response as all drug volume is no longer the limiting factor
What is affinity determined by?
Strength of chemical attraction between drug and receptor
A low Ec indicates high affinity
What is efficacy determined by?
How good the drug is at activating the receptor
What is the size of response dependent on?
- Drug affinity
- Drug efficacy
What do agonists do?
Mimic the normal effect of receptor
What do antagonists do?
Block the normal action of receptor
Give examples of transmitters that act on several receptor subtypes.
- ACh activates all cholinergic receptors, nicotinic and muscarinic
- Noraderenaline activates all adrenergic receptors,a1, a2, B1 and B2
What do selective agonists do?
Activate some but not all subtypes
-Salbutamol is a B2 agonsit
What do selective antagonists do?
Block some but not all subtypes
-Propanolol is a B1 and B2 antagonist
