Pharma 3 Vincent My Kink Flashcards
True or false
A change in V-1 or V2 composition does not vary the area under the curve
True
Because things change proportionally keeping the amount of medication the same
what is UGT 1A1
It is a glucuronidation enzyme that conjugates bilirubin with the glucoronic acid
What does a polymorphism in the phase two metabolism lead to
It depends on the type of medication whether it is the mother or the metabolite that is active
Generally speaking it can reduce the activity of the conjugation reactions which can lead to build up of the input
How many half lives does it take for medication to be gone
In general it takes five to seven half lives for no medication to be left
What is clearance
Clearance is the volume of blood that is purified from a medication per unit of time
It reflects the capacity of an organ to eliminate a medication from the blood
True or false
Clearance is independent of medication concentration in the blood
true
The clearance is a constant and does not depend on concentration but rather on the ability of the organ to clear the medication
Describe clairance
intrinsèque
It is the ability of an organ here of the liver to clear medication using the enzymatic activity
What are the three factors that modulate the biotransformation of a medication in the liver
- débit à l’organe (Q)
- liaison du médicament (M) aux protéines plasmatiques (PP),
- et activité des enzymes
Why is the strength of medication binding to plasmatic proteins a modulator of the liver’s transformation ability
Because only the medication that can free float and enter the liver ie that is not bound to plasma proteins or albumin can be modified
What are the two choices of the metabolite in the liver after the medication has been modified by the enzymes
It can either be eliminated to bile or it can be reabsorbed in the blood
For example when you give codeine it will go in the liver the enzymes will convert it into morphine and then some of that morphine will go back into the blood to exert its analgetic effect
What is the difference between a MÉDICAMENT DÉBIT-DÉPENDANT and a MÉDICAMENT DÉBIT-INDÉPENDANT
Imagine you’re at a party and the guests are the drugs in your body. The party is happening in a big house with many rooms (organs). The guests move from room to room (blood flow), and in each room, there’s a host who checks the guest list and decides who can stay and who has to leave (metabolism or excretion of the drug).
Médicament débit-dépendant (Flow-dependent drug): This is like a party where the hosts are very efficient and can quickly check the guest list. So, the number of guests leaving the party (drug clearance) depends on how many guests are moving from room to room (blood flow). If more guests move around (increased blood flow), more guests leave the party (increased drug clearance). An example could be aspirin.
This is dependent on how much drug you can bring in the organ.
Médicament débit-indépendant (Flow-independent drug): This is like a party where the hosts are less efficient and take a long time to check the guest list. So, even if more guests move from room to room (increased blood flow), it doesn’t significantly affect the number of guests leaving the party (drug clearance). An example could be warfarin.
This is dependent on the enzymes.
What type of medication in terms of blood flow would have a oral bioavailability that is similar to that of a iv bioavailability
In order for this to occur we need the number of enzymes that metabolize this medication to be low
This occurs in blood independent pharmacodynamics
What type of medication in terms of blood flow would be impacted by a change in intrinsic clearance through an increase of plasma protein binding
In order for this to have an effect we need to have a low intrinsic clearance and a large blood flow Q
As such medication that is blood flow independent will be affected by a change in plasma binding property but also enzyme enzyme inhibition or induction
What is the only thing that causes a change in CMAX CMAX elimination slope area under the curve and toxicity called a royal flush
The only thing that changes old properties it’s a change in metabolic clearance
What happens to a medication that is blood flow independent if we decrease its affinity for albumin
This means that the fraction that is free increases
Black flow independent means that the clearance of the medication is dependent on enzymatic clearance and amount of free medication
As such we have more free medication entering the liver so we increase its clearance therefore decreasing its available fraction decreasing its cmax etc
