pharmacokinetics 2

Question 1

Distribution

Answer 1

The transfer of drugs in and out of the various tissues of the body

Question 2

Diffusing across membranes

Answer 2

Only free or unbound drugs are available to diffuse across membranes

Question 3

Factors affecting drug distributing into various tissues of the body

Answer 3

1. The perfusion rate of the tissue (blood flow through the tissue)
2. The physiochemical ability of drug to cross membranes
3. The nature of the membranes
4. The extent to which the drug is bound

Question 4

Flow rate

Answer 4

Tissues that are well vascularised (plenty of blood vessels) such as the liver and the kidney will receive more of a drug than other parts of the body

Question 5

Distribution equilibrium

Answer 5

Is when the amount of drug entering the blood compartment is balanced by drug leaving that compartment

Question 6

Partition co-efficient

Answer 6

Partition coefficient (KP) determines the extent of drug entry into compartments.
It is the measure of a drug lipid solubility.

Question 7

Unionised drug

Answer 7

When the drug is unionised it readily crosses the membrane due to its lipid solubility

Question 8

Ionised drug

Answer 8

If drug becomes ionised, it become less lipid soluble and more water soluble, impacting its ability to cross cell membranes. But making it easier to be eliminated in the urine

Question 9

Basic drugs in a high pH (alkaline or basic environment)

Answer 9

are lipid soluble and therefore readily transported.

Question 10

Basic drugs in a low pH (acidic environment)

Answer 10

are far less lipid soluble and therefore not readily transported.

Question 11

Acidic drugs in a high pH (basic or alkaline environment)

Answer 11

are far less lipid soluble and therefore not readily transported.

Question 12

Acidic drugs in a low pH (acidic environment)

Answer 12

are lipid soluble and therefore readily transported.