Pharma Cardinal 1 Flashcards
Efficacité: Define In terms of pharmacodynamics
Efficacité
It is defined as the maximal response of medication
You can contrast a complete agonist versus a partial agonist and their maximal response at Max concentration
a complete agonist will have a stronger maximal response
Define power in terms of pharmacodynamics
Puissance
Power is defined as the amount of those required to give the same response where the medication requires less dose for a larger response is them one that is stronger
The more the curve is to the left the medication is stronger for example
This is sort of like the affinity of the drug for the receptor
Can two medication have the same efficacy but the different strength?
Yes they can
You can think of two medications where the dose to get a large response is different but at maximum saturation the maximum response is the same
What type of agonist is morphine
It is a complete agonist
What type of agonist is buprénorphine
Partial agonist
What is the standard medication that we use to compare the strength of other opioids
Morphine ten mg
What type of agonist is fentanyl
A complete agonist
What type of agonist is hydromorphone
Complete agonist
What receptor do all opioids act on
The mu opioid receptor
Explain the law of mass action
It stays at the interaction between an agonist and a receptor is reversible
Which leads to
An increase in agonist means more agonist will be bound to the receptor
A decrease in agonist means that less agonist will be bound to receptor
Depending on how much agonist is bound to the receptor that’s how much pharmacological effect we will get
A + R ->A-R → réponse biologique
What is the law of receptor occupation
It states that the intensity of a biological effect for medication is proportional to the amount of receptors that are occupied times the maximum tissue activity times the property of the drug
Define CE50
The concentration of drug required to reach 50% of Max effect
What is R*?
It is receptor that has been bound to a agonist and is in its active confirmation
It could also have spontaneous activity without binding to anagonist
What is the difference between a partial and complete agonist in terms of receptor activity
A complete agonist will stabilize the receptor in its active form
A partial agonist will not be able to stabilize the receptor in its active form so the receptor will switch between the two states
What is constitutive activity
It is when a gpcr receptor does the transition from R to R* spontaneously
Why do we say that a partial agonist can also act as a antagonist
the partial agonist does an incomplete stabilization of the receptor
The complete agonist does a complete stabilization of the receptor in its active configuration
It is the competition for the receptor between the complete and the partial agonist that leads to the partial agonist becoming an antagonist
(here there is no concept of affinity yet)
What is the key requirement for an inverse agonist
First of all an inverse agonist is basically an antagonist
It reduces the spontaneous activity of the Receptor
The requirement is therefore that the receptor must have some basal or constitutive activity
Can you have an inverse agonist that is complete or partial
Yes this is not reserved to +agonist
What is methadone
It is a complete agonist but with the long half-life
what is naloxone
don’t talk about properties just what it is
it is a neutral antagonist
Can a partial agonist be stronger than a complete agonist
Yes for example buprénorphine is twenty five times stronger than morphine although it is a partial agonist
Discuss bioavailability of naloxone
It has a trash baio availability orally sublingually
It must thus be administered intramuscularly or intravenously usually used to prevent opioid overdose
Describe the beauty of buprénorphine-naloxone
naloxone doesnt do anything when administered orally. So why give it?
Because if they try to break it and burn it to inject it, they will be injecting naloxone so they will lose the effect. Instead of just giving buprenophine
