Pharmacodynamics tutorial Flashcards
What is a drug?
A chemical substance that has a physiological response on a biological system
What is the heroin drug target site?
The nucleus accumbuns on the mew opoid receptor causing a sense of euphoria
How would heroin access the drug target site?
Heroin is lipid soluble so can cross the blood brain barrier and enter the brain
What are the four main categories of drug target sites?
Receptors (opioids, ach, atropine), ion channels eg LA, enzymes eg aspirin (cox) and transport systems (tca)
Why would heroin be more selective than alcohol?
It has more functional groups therefore will bind to a receptor with more complex binding pockets
How can tolerance occur after repeated use of a drug?
- receptor downregulation by loss of receptors
- receptor desensitisation by change in receptors
- physical adaptation where receptors aren’t signalling as well as before
What additional mechanisms could cause a tolerance to alcohol?
Alcohol dehydrogenase induction where alcohol broken down faster therefore more is needed for the same amount of inebriation
Exhaustion of mediator stores
How does Buprenorphine work to treat heroin addiction
Buprenorphine is a partial agonist. It means he can’t get a fatal overdose and will only stay at a certain euphoria. Therefore he will learn he doesnt need to increase the dose bc its pointless. Eventually maybe he copes with the lower amount and learns to live with it and eventually weans off the drug all together
