IV Bolus

Question 1

One compartment model

Answer 1

Treat the body as one

Absorption -> drug in body -> elimination

Question 2

Pharmacokinetics of an IV bolus injection

Answer 2

• Example of a one-compartment model
• Simplest possible representation of PK - drug goes in:
- drug comes out
- no complications

• Drug is injected IV as a bolus solution
• Drug is then removed passively through the kidneys into the urine for excretion
• No metabolism, no protein binding, no sequestration by other tissues

Question 3

Two compartment model

Answer 3

Drug in peripheral compartment
I ^ Distribution
V I
Absorption -> drug in central compartment -> emilination

The two- compartment model can be viewed as such in which drug distributes from the central compartment, of which plasma is a part, to the peripheral compartment, which is viewed as tissues.

Question 4

Major assumption

Answer 4

Assumption that drug is already in circulation and already distributed

At time = 0, the drug is completely and evenly distributed throughout the plasma

Question 5

Main pharmacokinetics parameters

Answer 5

• Volume of Distribution
• Clearance
• Exposure
• Mean residence time - how fast it is removed
• Fraction of dose remaining

Use conc/time to work these out

Question 6

Look back at notes for graphs

Question 7

Volume of distributor predicts the……

Answer 7

Concentration for a given amount of drug i the body

Question 8

Clearance?

Answer 8

Relates the rate of elimination to the concentration in the systemic circulation - estimation of the rate of elimination at any concentration

Question 9

First order elimination

Answer 9

How fast the drug concentration declines from the reservoir

Similar to reaction rates of kinetics on laszlo slides