Concentration And Response

Question 1

Difference in concentration time graph for iv verses oral drug

Answer 1

Oral drug takes time to absorb
Iv drug has no absorption phase

Question 2

Pro-drugs require what before they are active?

Answer 2

Metabolic step

Question 3

What metabolic step does clopidogrel undergo?

Answer 3

Requires oxidation and hydrolysis (liver enzyme mediated)

Question 4

Sulfasalazine is metabolised by? What is active metabolite?

Answer 4

Intestinal bacteria
Active metabolite= sulfapyridine

Question 5

Why isn’t giving active component not useful?

Answer 5

May be absorbed before reaching target
May have adverse effects

Question 6

Pharmacological effects depend on?

Answer 6

-Active molecule reaching the site of action
- Adequate concentration at the site of action

Question 7

Pk factors that determine concentration of a drug at its target

Answer 7

Dose
Absorption (formulation, host factors eg.diarrhoea or patient just had surgery)
Distribution

Question 8

Therapeutic index is defined as the ratio between?

Answer 8

EC50 and TC50

Question 9

Difference between therapeutic effect and toxic effect determines?

Answer 9

Determines the difference between a therapeutic and toxic dose