F1. Intro to Pharmacology Flashcards
drug
A substance that alters chemical reactions in the body
two properties of a drug to consider?
-exerts a selective physiological effect
-A compound with a defined chemical structure
what do drugs usually target
proteins
what are 4 major classes of protein targets?
-enzymes
-transporters
-ion channels
-receptors
receptors
proteins which respond to a endogenous messenger by initiating a signal
what are common characteristics with all recepetors?
-selective binding site for native hormone/ transmitter
-act as molecular switches (inactive and active states)
-signal is amplified (one note)
what are the two types of receptor drugs?
agonists and antagonists
agonists?
reproduce the effects of endogenous messenger
antagonists?
blocks the effects of endogenous messenger
what type of drug targets enzymes, transporters and ion channels?
on type of drug- inhibitors
what does the effect of a drug depend on?
concentration of the drug at target site- two processes influence the therapeutic dose (supply and removal)
pharmacokinetics?
how body controls drug concentration at site of action
pharmacodynamics?
effect of drug on target
Pharmacokinetics parameters are abbreviated as….
ADME[Tox]”
Absorption
Distribution
Metabolism
Excretion
Toxicity
Describe drug selectivity
-it interacts with the binding site of the “correct” molecular target. (e.g asthma- one note)
-on-target versus off-target effects leading to why all drugs have benefits and risks
on target effect?
means effect produced by intended interaction with the correct molecular target
off target effect?
means effects produced by unintended interaction with a different molecular target
adrenaline receptors?
adrenoreceptors (one note)
what does the strength of an interaction between a drug and its protein target depend on?
depends on ability for drug molecule to bind to 3D protein binding site- affinity. The better the fit, the higher the affinity the drug has for its target- producing its effect at lower concentration.- important for drug selectivity.
Describe salbutamol
higher affinity for adrenoceptors in the lungs than in the heart, lowering effect on the heart and allows for effect on the lungs to treat asthma. However at high doses, salbutamol will activate heart adrenoceptors and cause increased heart rate.
