Essential Pharmacology 2 Flashcards
What is pharmacology?
The study of the effect of drugs on living systems
What is a drug?
Any chemical agent that affects a biological system
What are some sources of drugs?
Plants
Synthetic drugs
Biotechnology to make therapeutic agents using living systems
Gene therapy to introduce new DNA
How do drugs act?
By interacting with the binding site of a receptor
What is the relationship between drug concentration and the size of the response?
Low drug concentrations produces a small response and high drug concentration produces a large response, this is due to more receptors being activated
When do receptors become saturdated?
When all of them are binded so no increase in drug concentration could produce a larger response
Why does the response become slower as receptors near saturation?
The probability of a drug bumping into a receptor is lower
What does the log of [drug] against percentage of saturation look like?
What is EC50?
Concentration of a drug that produces half of the maximum effect (quantifies affinity)
What is affinity?
The strength of the chemical attraction between drug and receptor
What does EC50 indicate about affinity?
A low EC50 indicates a high affinity
Do drugs always fully activated a receptor?
No, they can be partly activated (such as partly opening a channel or partly activating an enzyme)
What is efficacy?
How good the drug is at activating the receptor
What does the efficacy indicate about the EC50 and the maximum response?
A lower efficacy has the same EC50 but a smaller maximum response
What does the size of response from a drug depends on?
Drug affinity
Drug efficacy
What is an agonist?
Mimics the normal effect of receptor
What is an antagonist?
Blocks the normal effect of a receptor
What is the affinity and efficacy of agonists?
High affinity
High efficacy
What is the affinity and efficacy of an antagonist?
High affinity
Low efficacy
How do tranmitters interact with different kinds of receptors?
Ome may act of several receptor subtypes, whereas selective transmitters only act on some of the subtypes
What can selective agonists be used for?
Enhance a good effect
What can selective antagonists be used for?
Blocking bad effects
