OPIODS

Question 1

what is the nitrogen side chain in morphine important for?

Answer 1

this side chain is important in anchoring the drug to the receptor.

Question 2

what side chain is changes when making heroin and coedine from morphine?

Answer 2

heroin: both hydroxyl groups–> carboxyl groups
coedine: hydroxyl group on 3rd carbon –> CH3)

Question 3

what happens to the ionization of opiods as they go through the GIT?

Answer 3

opiods are weak bases
in the stomach which is very acidic the opoid donates protons and becomes ionized (poor absorption in the stomach)

further down the GIT the lumen becomes more alkaline and the opiod gets less ionized so can be absorbed better.

Question 4

what are the activating and deactivating metabolising enzymes for morphine?

Answer 4

activate- CYP2D6

deactivate - CYP3A4

Question 5

what are the endogenous opioid peptids?

Answer 5

endorphins
enkephalines
dynorphines

Question 6

what does the opioid do when it binds to the receptor?

Answer 6

depressant 
causes hyperpolarisation (decrease K+)

decreases Ca2+ influx so reduces NT release

decreases the activity of adenylate cyclase

Question 7

what are the 3 classes of opioid receptor?

Answer 7

Mu, delta, kappa

Question 8

what are the effects of opioids?

Answer 8

analgesia (decrease in pain)
euphoria
depression of cough center