Flashcards in Pharmacology 2 Deck (14):
Describe some of the sources of drugs?
Natural products from nature
Synthetic drugs from the pharmaceutical industry
Biotechnology using living systems to make therapeutic agents.
How do drugs act?
Interfering with a binding site - a receptor
Give examples of binding sites
Cell surface and intracellular receptors
When will you get the maximum response from a drug?
When all the relevant receptors are bound to the drug
What is the affinity of a drug?
It is the strength of chemical attraction between the drug and the receptor
Why is the concentration / response graph curved?
Because it is more likely for a ligand to hit a free receptor at the start of a reaction then the end
What graph is used to determine the EC50?
The log of drug concentration against the increasing response
What is the EC50?
It is the concentration of a drug at half of its maximal response
What does the EC50 indicate?
The affinity of the drug for the receptor, a smaller EC50 indicates a smaller amount of drug is needed to evoke the same response, therefore the drug has a higher affinity
What does efficacy determine?
It determines how good the drug is at activating the receptor
How does efficacy affect the EC50
What is an agonist?
It mimics the normal effect of the receptor
What is an antagonist?
It blocks the normal effect of the receptor