Essential Pharmacology Pt2 Flashcards
What are endogenous chemical agents?
made by the body e.g. neurotransmitters and hormones
What are exogenous chemical agents?
e.g. drugs
What is basic def of a drug?
chemical agent that affects biological system
What are the different types of receptors?
Cell surface receptors e.g. β-adrenergic receptors
Intracellular receptors e.g. steroid receptors
Ion channels e.g. TTX blocks Na+ channels
Carriers e.g. ouabain inhibits Na+/K+-ATPase
Enzymes e.g. aspirin and ibuprofen inhibit cyclooxygenase
Nucleic acids e.g. tumour promoters bind to DNA
What would happen if drug mols are increased but receptor mols are not?
cannot increase response further. Have reached saturation
What does EC50 tell us?
the measure of affinity of drug
the conc at which drug achieves 50% of max response
What are characteristics of drug with higher affinity?
need smaller % of drug to reach max response
lower EC50
How is affinity determined?
Affinity is determined by strength of chemical attraction between drug and receptor - low EC50 indicates high affinity
What is efficacy?
determined by how good drug is at activating the receptor
What is an agonist?
Agonists mimic normal effect of receptor
What is an antagonist?
Antagonists block normal action of receptor
What are the properties of full agonist?
high affinity for receptor and high efficacy
What are properties of partial agonist?
high affinity but low efficacy
What are properties of antagonist?
high affinity low efficacy
Why are antagonists useful?
block physiological response
