Question 1

Regarding receptor regulation

Accepted Answer

A)  Receptor down regulation occurs over hours - days
B)  Receptor responses to drugs often "desensitise" with time - this desensitisation is usually irreversible
C)  The mechanism of agonist induced desensitisation of the nicotinic Ach receptor has been worked out in detail
D)  All "internalised" receptors are degraded by lysosomes
E)  None of the above are correct A

Question 2

Which of the following has ? bioavailability in the neonate when compared with older children/adults?

Accepted Answer

A)  Penicillin
B)  Digoxin
C)  Acetaminophen
D)  Diazepam
E)  Phenobarbital A

Question 3

Volume of distribution equals

Accepted Answer

A)  Dose given/plasma concentration
B)  Total amount of drug in the body/plasma concentration
C)  Urine drug concentration/plasma concentration
D)  Dose given/urine concentration
E)  Urine drug concentration/plasma concentration. B

Question 4

A single compartment model means that

Accepted Answer

A)  One exponential term describes the decreasing plasma concentration of the drug
B)  A single exponential term describes the rise in plasma concentration following oral administration
C)  The drug does not penetrate tissues
D)  The drug is restricted to the ECF
E)  The drug is highly ionised

Question 5

A D Response B C Concentration Which of these drugs is the most efficacious?

Accepted Answer

A)  Drugs A and B
B)  Drug C
C)  Drugs A and D
D)  Drugs D and C
E)  Drug A

Question 6

Which of the following drugs undergoes rate limited elimination?

Accepted Answer

A)  Lignocaine
B)  Morphine
C)  Warfarin
D)  Propanolol
E)  Aspirin

Question 7

Ligand gated channel receptors include all of the following EXCEPT

Accepted Answer

A)  GABA
B)  Aspartate
C)  Glycine
D)  Glutamate
E)  Ach-muscarinic

Question 8

Which of the following will NOT alter the volume of distribution of a drug?

Accepted Answer

A)  Cardiac failure
B)  Clearance
C)  Age
D)  Burns
E)  Pleural effusion

Question 9

Which of the following undergoes a phase I hydrolysis reaction? (biotransformation)

Accepted Answer

A)  Ethanol
B)  Naloxone
C)  Morphine
D)  Lignocaine
E)  Diazepam

Question 10

Which of the following undergoes acetylation in the liver? (Phase 2 biotransformation)

Accepted Answer

A)  Isoniazid
B)  Acetaminophen
C)  Salicylic acid
D)  Epinephrine
E)  Diazepam

Question 11

First order kinetics

Accepted Answer

A)  Means rate of reaction is proportional to concentration
B)  Are more common than zero order kinetics
C)  Apply to exponential processes
D)  Generally apply to high plasma concentrations (>20mg/100ml)  of ethanol
E)  Result in steady state concentrations after multiple dosing

Question 12

Which of the following acts on intracellular receptors

Accepted Answer

A)  Serotonin
B)  Glucagon
C)  Corticosteroids
D)  GABA
E)  Insulin

Question 13

EC50 is

Accepted Answer

A)  Measured with a radioactive receptor
B)  Always equal to Kd
C)  Drug concentration with 50% receptors bound
D)  Representation of the receptors affinity for drug binding
E)  Drug concentration with 50% of maximal drug effect

Question 14

All of the following drugs exhibit flow dependent elimination EXCEPT

Accepted Answer

A)  Atenolol
B)  Isoniazid
C)  Propoxyphene
D)  Amitriptylline
E)  Lignocaine

Exam 2: Drug Elimination, Biotransformation, Receptor Regulation, and Kinetics