Clearance Flashcards
Halfwaarde tijd
Tijd waarin de helft van het medicijn uit je lichaam is
Elimination
Metabolism and excretion. The drug doesn’t have to be out of the body to be eliminated
Excretion
Removal of the drug from the body
Can be active of passive
When is a constant amount removed?
When there is more substrate then there are pumps
Why is only a fraction of the drug removed when there are enough pumps?
Not all the drug is in the blood, so not everything can be removed by the kidney
Per cycle, a fixed % is cleared: true of false?
True
Q
Bloodflow
C_A
Arterial concentration
C_V
Venous concentration
Formule: Amount that passes the pump (kidney)
Q x C_A
Formule: Amount removed
Q (C_A - C_V)
Formule: Removed fraction
C_A - C_V / C_A
Formule: Clearance
(C_A - C_V / C_A) x Q
Clearance definition
The volume from which the drug is removed
Formule: More practical way to measure the clearance
Cl x C_A = Q (C_A - C_V)
Dat laatste is the amount removed en dat is makkelijk meten dan dialysis
Formule: dose
Dose = Vd x C0 / F = clearance X AUC
Dose is related to AUC
- What happens when you have a steeper curve than before?
Lower clearance, so bad kidney function
Dose is related to AUC
- What happens when your curve bends instead of it being linear
when the dose gets higher, you get a even higher exposure
AUC definition
the exposue of the drug to the body
