Efficacy and Partial Agonists Flashcards
1
Q
What is efficacy and what does it depend on?
A
- The ability of a drug to activate a receptor and cause a response (EFFECT)
- Depends on the number of receptors occupied and
2
Q
What is E max?
A
The maximum response an agonist can achieve
3
Q
What type of Emax does a partial agonist have?
A
Lower Emax
4
Q
What is a partial agonist?
A
They partially bind to the receptor sites and can never evoke the maximum Emax response even though 100% of receptor sites may be binded
5
Q
How is a partial agonist used in medicines and give an example?
A
- Used due to less desensitisation compared to normal agonists and can be used as competitive inhibitors against agonists
- Buprenorphine- used as a partial agonist as it reduce pain but not give all the other side effects of morphine
6
Q
What is the term that explains how maximum response can be created without 100% of the receptor sites being binded and explain it?
A
- Receptor Reserves- a proportion of receptors in the tissues that are never used
- A signal amplification must occur for it to activate
7
Q
What is the inverse agonist?
A
- Has some actions that are similar to agonists but can also have the complete opposite response- it blocks the individual activity of the agonist as well (not just receptors)
- Equilibrium between agonist and inverse as they switch between the two
8
Q
What are state are receptors constantly in? And which do agonists prefer?
A
- Constant equilibrium between active and non active state
2. Agonists prefer the active state