Lecture 3 Qs - Questions on Mechanisms of Drug Action

Question 1

A 4 year old girl is bitten by a Tiger snake whilst holidaying in Australia. An anti-venom (harvested antibodies) is administered. Which form of antagonism is utilised by the anti-venom?

A) Competitive receptor blockade
B) Physiological antagonism
C) Chemical antagonism
D) Pharmacokinetic antagonism
E) Irreversible receptor blockade

Answer 1

C - Chemical antagonism

The two substances interact in solution with the anti-venom detoxifying the venom before it can have its damaging effect.

Question 2

Tolerance to the euphoric effects of drugs of abuse (e.g. heroin and cocaine) can occur after repeated use. Which form of tolerance would not involve any change in the cells that mediate the euphoric effects?

A) Receptor desensitisation
B) Receptor down-regulation
C) Exhaustion of mediator stores
D) Receptor up-regulation
E) Increased metabolic degradation

Answer 2

E - Increased metabolic degradation

All other options include structural changes in the cell and receptors. This option is likely that the cell increases the number of metabolic enzymes that breakdown the drugs or increases the speed with which the drugs are broken down.