Pharmacological Principles | Set 1

1. Which of the following is >90% bound to plasma proteins?

2. Which of the following has the largest volume of distribution?

4. Which of the following is a phase one reaction?

6. An example of drugs that undergo chemical antagonism is

A. Insulin - glucagon

B. Protamine - heparin

C. Prednisone - glipizide

D. Morphine - naloxone

E. Phenoxybenzamine - prazosin

Correct : B. Protamine - heparin

7. Regarding first order kinetics - all of the following are true EXCEPT

A. First order kinetics means rate of reaction is proportional to concentration

B. First order kinetics is more common than zero order kinetics

C. First order kinetics apply to exponential processes

D. First order kinetics generally apply to high plasma concentrations (>20 mg / 100 ml) of ethanol

E. First order kinetics result in steady state concentrations after multiple dosing.

Correct : D. First order kinetics generally apply to high plasma concentrations (>20 mg / 100 ml) of ethanol

8. Bioavailability is

A. The difference between the amount of drug absorbed and the amount excreted

B. The proportion of the drug in a formulation that is found in the systemic circulation

C. The AUC relating plasma concentration of drug to time after administration

D. Always identical with different formulations of the same drug

E. A measure of the rate of absorption of a drug

Correct : B. The proportion of the drug in a formulation that is found in the systemic circulation

10. What is the half life of a drug with a volume of distribution of 700l/70kg and clearance of 49l/hour/70kg?

11. Regarding biotransformation

A. Phase one reactions always precede phase two reactions

B. Skin is an organ involved in drug biotransformation

C. Water conjugation is a phase one reaction

D. CYP2D6 accounts for the majority of P450 activity

E. Epoxidation is phase two biotransformation

Correct : B. Skin is an organ involved in drug biotransformation

12. Which of the following receptor - ligand pathway is correct?

A. Insulin - G protein receptor

B. Mineralocorticoid - tyrosine kinase receptor

C. Vitamin D - intracellular receptor

D. Adrenaline - ligand gated channel receptor

E. Platelet derived growth factor - cytokine receptor

Correct : C. Vitamin D - intracellular receptor

13. Age associated changes in pharmacokinetics include

A. Reduction in creatinine clearance in 2/3 population

B. Decreased body fat

C. Increase body water

D. A greater reduction in conjugation compared with oxidation

E. A decreased absorption related to age alone

Correct : A. Reduction in creatinine clearance in 2/3 population

14. The metabolic pathway of detoxification that become increasingly important in paracetamol toxicity is

A. Conjugation with glucuronide

B. Oxidation

C. Reduction

D. Methylation

E. Cytochrome p450 dependent glutathione conjugation

Correct : E. Cytochrome p450 dependent glutathione conjugation

15. You are given a vial with 15 ml of 0.5% prilocaine to do an arm block. How many mg of prilocaine are you injecting?

16. Drugs that enhance other drug metabolism include all of the following EXCEPT

18. Regarding pharmacology principles

A. Diffusion is directly proportional to thickness and inversely proportional to surface area

B. LD50 - 50% of the dose that kills most people

C. Efficacy is the maximum response produced by a drug

D. A partial agonist is always less potent than a full agonist

E. EC50 = concentration of agonist that results in maximal response in 50% of patients

Correct : C. Efficacy is the maximum response produced by a drug

19. Reports of cardiac arrhythmias caused by unusually high blood levels of 2 antihistamines (terfenadine and astemizole) are best explained by

A. Concomitant treatment with phenobarbital

B. Use of these drugs by smokers

C. Use of antihistamines by persons of Asian background

D. A genetic predisposition to metabolise succinylcholine slowly

E. Treatment of these patients with ketoconazole

Correct : E. Treatment of these patients with ketoconazole

20. Which of the following statements is correct?

A. The half life is the time taken for a parameter to fall to 1/4 its original value

B. Partial agonists act at receptor sites to cause maximal pharmacological effect at high doses

C. Diazepam has a high extraction ratio and is thus subject to flow dependent elimination

D. Morphine and pethidine have the same potency

E. A patient with oedema will have an increased volume of distribution of tobramycin

Correct : E. A patient with oedema will have an increased volume of distribution of tobramycin

21. Which of the following drugs has an average half life of 50 hours?

23. All of the following drugs are >90% plasma protein bound EXCEPT

24. Which of the following drugs has a volume of distribution >2000 ℓ/70kg?

25. What is the half life of a drug with a volume of distribution of 100ℓ/70kg and a clearance of 7ℓ/hr/70kg

26. All of the following drugs exhibit flow dependent elimination EXCEPT

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

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

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

31. EC50 is

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

Correct : E. Drug concentration with 50% of maximal drug effect

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

33. Volume of distribution equals

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

Correct : B. Total amount of drug in the body/plasma concentration

35. Ligand gated channel receptors include all of the following EXCEPT

36. Regarding receptor regulation

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

Correct : A. Receptor down regulation occurs over hours – days

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

39. First order kinetics

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

Correct : D. Generally apply to high plasma concentrations (>20mg/100ml) of ethanol

40. A single compartment model means that

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

Correct : A. One exponential term describes the decreasing plasma concentration of the drug

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