Podcast
Questions and Answers
What does the liver extraction ratio (ER) measure?
What does the liver extraction ratio (ER) measure?
- General distribution of the drug in the body
- Drug concentration in the liver
- Blood flow to the liver
- Drug removal from the liver after oral administration (correct)
What does an ER of 0.25 indicate?
What does an ER of 0.25 indicate?
- 100% of the drug is removed by the liver
- 75% of the drug is removed by the liver
- 25% of the drug is removed by the liver (correct)
- 50% of the drug is removed by the liver
How is hepatic clearance (Clh) calculated if both the ER and the blood flow to the liver are known?
How is hepatic clearance (Clh) calculated if both the ER and the blood flow to the liver are known?
- Clh=Q-ER
- Clh=Q×Ca-Cv/Ca
- Clh=Ca/Cv
- Clh=Q×ER (correct)
Why is sampling of drug from the hepatic portal vein and artery difficult?
Why is sampling of drug from the hepatic portal vein and artery difficult?
Why may animal ER values be quite different from those in humans?
Why may animal ER values be quite different from those in humans?
Which factor(s) affect the hepatic clearance of a drug?
Which factor(s) affect the hepatic clearance of a drug?
What is the relationship between bioavailability (F), liver extraction (ER), and fraction of drug removed by nonhepatic process (F″)?
What is the relationship between bioavailability (F), liver extraction (ER), and fraction of drug removed by nonhepatic process (F″)?
For drugs with very high extraction ratios, how does the rate of drug metabolism respond to changes in hepatic blood flow?
For drugs with very high extraction ratios, how does the rate of drug metabolism respond to changes in hepatic blood flow?
What is used to describe the total ability of the liver to metabolize a drug in the absence of flow limitations?
What is used to describe the total ability of the liver to metabolize a drug in the absence of flow limitations?
What can increase the intrinsic clearance for the metabolism of many drugs?
What can increase the intrinsic clearance for the metabolism of many drugs?
What does a liver extraction ratio (ER) value of 0.25 indicate?
What does a liver extraction ratio (ER) value of 0.25 indicate?
How is hepatic clearance (Clh) calculated when both the liver extraction ratio (ER) and the blood flow to the liver are known?
How is hepatic clearance (Clh) calculated when both the liver extraction ratio (ER) and the blood flow to the liver are known?
What factor(s) affect the hepatic clearance of a drug?
What factor(s) affect the hepatic clearance of a drug?
Why may animal ER values be quite different from those in humans?
Why may animal ER values be quite different from those in humans?
What does the liver extraction ratio (ER) provide a direct measurement of?
What does the liver extraction ratio (ER) provide a direct measurement of?
In the context of hepatic clearance, what is the significance of intrinsic clearance (Clint)?
In the context of hepatic clearance, what is the significance of intrinsic clearance (Clint)?
What characterizes drugs with high extraction ratios in terms of hepatic clearance?
What characterizes drugs with high extraction ratios in terms of hepatic clearance?
What factor primarily affects drugs with low extraction ratios in terms of hepatic clearance?
What factor primarily affects drugs with low extraction ratios in terms of hepatic clearance?
How does propranolol, a beta-adrenergic blocking agent, affect its own hepatic clearance when given orally?
How does propranolol, a beta-adrenergic blocking agent, affect its own hepatic clearance when given orally?
What condition can increase the intrinsic clearance for the metabolism of many drugs?
What condition can increase the intrinsic clearance for the metabolism of many drugs?
