drug action Flashcards
what are the 4 main modes of drug action?
activation or blocking of receptors
activating or blocking enzyme function
opening or blocking ion channels
facilitation or blocking transport systems
what else might the drug interact with?
coupled to ion channels
coupled to G-proteins
coupled to enzymes
coupled to gene transcription
what is affinity?
the tightness of the drug binding to the receptor
what is occupancy?
how much time the drug spends on the receptor
what is efficacy?
how effective the drug is at producing a response from the receptor
what is the law of mass action?
the higher the drug concentration the more receptors will be occupied at any one time and the more response will be achieved
what is an agonist?
bind to a receptor and cause an expected effect
what are partial agonists?
more difficult to produce the drug/receptor effect than with an agonist
increase partial agonist conc will improve efficacy for some
what is a non-competitive antagonist?
binds separately, doesn’t compete
reduces available receptors for the agonist
affinity & occupancy rules font apply
cant manage with agonist
what is a competitive antagonist?
binds at same site
can be managed by increasing conc. of agonist
what is an enzyme?
remains unchanged at the end of their normal reaction
may join or break existing substances
what are the stages of enzyme action?
substrate entering active site of enzyme enzyme/substrate complex -enzyme changes shape slightly as substrate binds enzyme/products complex products leave active site of enzyme
what drugs can change enzyme action?
aspirin
simvastatin
how can drugs change enzyme action?
substrate antagonism-competitive
non-competitive substrate inhibition
what changes can ion channels produce?
cell electrical activity
ion influx
