Session 1

Question 1

How do you calculate steady state concentration in plasma?

Answer 1

CpSS = dose rate / clearance

Question 2

How do you calculate loading dose?

Answer 2

Volume of distribution x CpSS

Question 3

What is the difference between zero order and first order kinetics?

Answer 3

Zero (non-linear) = rate of elimination is constant. No half-life can be defined.

1st (linear) = rate of elimination is proportional to drug level. Constant fraction of drug is eliminated in unit time. Elimination becomes non-linear at higher levels.

Question 4

What is clearance?

Answer 4

The volume of plasma that is completely cleared of the drug per unit time.

Question 5

How do you calculate half life?

Answer 5

T1/2 = (0.693 x Vd)/clearance

Question 6

Name CYP inhibitors

Answer 6

G- grapefruit juice
O- omeprazole
D- disulfiram
E- erythromycin
V- valproate
I- isoniazid
C- cimetidine/ciprofloxacin
E- ethanol
S- sulphonamides

Question 7

Name CYP inducers

Answer 7

P- phenytoin
C- carbamezepine
B- barbiturates
R- rifampicin
A- alcohol
S- sulphonylureas

Question 8

Describe phase 1 and phase 2 of drug metabolism

Answer 8

1 = oxidation/reduction/hydrolysis via CYP 450
2 = conjugation with glucoronyls/sulphates/methyls/acetyles etc.

Question 9

How do you calculate volume of distribution?

Answer 9

Total amount of drug in the body / plasma concentration of drug at time zero

Question 10

What are the major fluid compartments of the body?

Answer 10

Plasma, extracellular and intracellular fluid.

Question 11

What factors affect drug distribution?

Answer 11

Lipophilicity (moves from blood plasma to tissues)
Hydrophobicity
Plasma binding reduces entry into tissues.
Amount of tissue and density of binding sites within that tissue.

Question 12

How do you calculate bioavailability?

Answer 12

Amount of drug reaching systemic circulation / total amount of drug given

Question 13

How do you calculate oral bioavailability?

Answer 13

The amount getting in orally / Total amount administered via IV.

Question 14

What are parenterally delivered drugs?

Answer 14

Do not involve the GI tract. E.g. IV, subcutaneous, transdermal, intramuscular and intrathecal.

Question 15

What are black triangle drugs?

Answer 15

They are being intensively monitored.
Newly released, changed indications, changed formulations or combination products.
Yellow cards must be submitted for the drugs for all suspected reactions.