L39 - Drug Elimination - Excretion 2 Flashcards
(7 cards)
1
Q
What is the rate of renal excretion for a drug eliminated by? (2)
A
- glomerular filtration
- tubular secretion
2
Q
What happens to ClR when rate of renal excretion eliminated by 2 mechs?
A
Exceeds its rate of filtration
ClR = funbound x ClR + Clsecretion
3
Q
What happens to renal clearance as unbound fraction increases? (2)
A
- the renal clearance increases
- more filtered, more secreted
4
Q
What is active secretion like?
A
As you double conc of drug in plasma, excretion rate doubles
until the transporters fully saturated
5
Q
What happens when rate of renal excretion for a drug eliminated by glomerular filtration and reabsorbed? (2)
A
- CiR will be less than its rate of filtration
- ClR = funbound x Clcr - Clreabsorption
6
Q
What factors determine passive reabsorption? (2)
A
- gradient established (more diluted, smaller grad, less reabsorption
- MW
7
Q
How can you increase ClR with urine pH?
A
Decrease reabsorption by ionising drug
