MCQOPTIONS
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MCQOPTIONS
This section includes 39 Mcqs, each offering curated multiple-choice questions to sharpen your Biology knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
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 |
| Answer» F. | |
| 2. |
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 |
| Answer» B. A single exponential term describes the rise in plasma concentration following oral administration | |
| 3. |
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 |
| Answer» E. Result in steady state concentrations after multiple dosing | |
| 4. |
Which of the following acts on intracellular receptors |
| A. | Serotonin |
| B. | Glucagon |
| C. | Corticosteroids |
| D. | GABA |
| E. | Insulin |
| Answer» D. GABA | |
| 5. |
Which of the following is >90% bound to plasma proteins? |
| A. | Atenolol |
| B. | Diazepam |
| C. | Gentamycin |
| D. | Lithium |
| E. | Theophylline |
| Answer» C. Gentamycin | |
| 6. |
Which of the following has the largest volume of distribution? |
| A. | Digoxin |
| B. | Imipramine |
| C. | Lithium |
| D. | Chloroquine |
| E. | Trimethoprim |
| Answer» E. Trimethoprim | |
| 7. |
Which of the following has the shortest half life? |
| A. | Theophylline |
| B. | Diazepam |
| C. | Aspirin |
| D. | Lithium |
| E. | Digoxin |
| Answer» D. Lithium | |
| 8. |
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. |
| Answer» E. First order kinetics result in steady state concentrations after multiple dosing. | |
| 9. |
Which of the following is a phase one reaction? |
| A. | Reduction |
| B. | Acetylation |
| C. | Glucuronidation |
| D. | Methylation |
| E. | Sulphate conjugation |
| Answer» B. Acetylation | |
| 10. |
Clearance of which drug involves capacity limited elimination? |
| A. | Theophylline |
| B. | Gentamycin |
| C. | Digoxin |
| D. | Lithium |
| E. | Phenytoin |
| Answer» F. | |
| 11. |
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 |
| Answer» B. Receptor responses to drugs often desensitise with time this desensitisation is usually irreversible | |
| 12. |
An example of drugs that undergo chemical antagonism is |
| A. | Insulin - glucagon |
| B. | Protamine - heparin |
| C. | Prednisone - glipizide |
| D. | Morphine - naloxone |
| E. | Phenoxybenzamine - prazosin |
| Answer» C. Prednisone - glipizide | |
| 13. |
All of the following drugs exhibit flow dependent elimination EXCEPT |
| A. | Atenolol |
| B. | Isoniazid |
| C. | Propoxyphene |
| D. | Amitriptylline |
| E. | Lignocaine |
| Answer» B. Isoniazid | |
| 14. |
Which of the following drugs undergoes rate limited elimination? |
| A. | Lignocaine |
| B. | Morphine |
| C. | Warfarin |
| D. | Propanolol |
| E. | Aspirin |
| Answer» F. | |
| 15. |
A D Response B C Concentration Which of these drugs is the most efficacious? |
| A. | Drugs A and B |
| B. | Drug C |
| C. | Drugs A and D |
| D. | Drugs D and C |
| E. | Drug A |
| Answer» D. Drugs D and C | |
| 16. |
Which of the following undergoes acetylation in the liver? (Phase 2 biotransformation) |
| A. | Isoniazid |
| B. | Acetaminophen |
| C. | Salicylic acid |
| D. | Epinephrine |
| E. | Diazepam |
| Answer» B. Acetaminophen | |
| 17. |
Which of the following undergoes a phase I hydrolysis reaction? (biotransformation) |
| A. | Ethanol |
| B. | Naloxone |
| C. | Morphine |
| D. | Lignocaine |
| E. | Diazepam |
| Answer» E. Diazepam | |
| 18. |
Which of the following will NOT alter the volume of distribution of a drug? |
| A. | Cardiac failure |
| B. | Clearance |
| C. | Age |
| D. | Burns |
| E. | Pleural effusion |
| Answer» C. Age | |
| 19. |
Referring to the graph in question 9 which of the drugs is most potent? |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| E. | A and B |
| Answer» B. B | |
| 20. |
Ligand gated channel receptors include all of the following EXCEPT |
| A. | GABA |
| B. | Aspartate |
| C. | Glycine |
| D. | Glutamate |
| E. | Ach-muscarinic |
| Answer» F. | |
| 21. |
Which of the following has bioavailability in the neonate when compared with older children/adults? |
| A. | Penicillin |
| B. | Digoxin |
| C. | Acetaminophen |
| D. | Diazepam |
| E. | Phenobarbital |
| Answer» B. Digoxin | |
| 22. |
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 |
| Answer» C. Urine drug concentration/plasma concentration | |
| 23. |
What is the half life of a drug with a volume of distribution of 700l/70kg and clearance of 49l/hour/70kg? |
| A. | 5 hours |
| B. | 7 hours |
| C. | 10 hours |
| D. | 12.5 hours |
| E. | 15 hours |
| Answer» D. 12.5 hours | |
| 24. |
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 |
| Answer» C. The AUC relating plasma concentration of drug to time after administration | |
| 25. |
Which of the following drugs has a high extraction ratio? |
| A. | Diazepam |
| B. | Theophylline |
| C. | Phenytoin |
| D. | Warfarin |
| E. | Propranolol |
| Answer» F. | |
| 26. |
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 |
| Answer» C. Water conjugation is a phase one reaction | |
| 27. |
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 |
| Answer» D. Adrenaline - ligand gated channel receptor | |
| 28. |
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 |
| Answer» B. Decreased body fat | |
| 29. |
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? |
| A. | 7.5 mg |
| B. | 15 mg |
| C. | 30 mg |
| D. | 50 mg |
| E. | 75 mg |
| Answer» F. | |
| 30. |
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 |
| Answer» F. | |
| 31. |
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 |
| Answer» D. A partial agonist is always less potent than a full agonist | |
| 32. |
Which is the safest to give in pregnancy? |
| A. | Lithium |
| B. | Phenytoin |
| C. | Gentamycin |
| D. | Heparin |
| E. | ACE inhibitors |
| Answer» E. ACE inhibitors | |
| 33. |
Drugs that enhance other drug metabolism include all of the following EXCEPT |
| A. | Rifampicin |
| B. | Ketoconazole |
| C. | Phenobarbital |
| D. | Griseofulvin |
| E. | Phenytoin |
| Answer» C. Phenobarbital | |
| 34. |
What is the half life of a drug with a volume of distribution of 100 /70kg and a clearance of 7 /hr/70kg |
| A. | 5 hours |
| B. | 10 hours |
| C. | 12.5 hours |
| D. | 15 hours |
| E. | 20 hours |
| Answer» C. 12.5 hours | |
| 35. |
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 |
| Answer» F. | |
| 36. |
Which of the following drugs has an average half life of 50 hours? |
| A. | Nortriptylline |
| B. | Digoxin |
| C. | Trimethoprim |
| D. | Valproic acid |
| E. | Lithium |
| Answer» C. Trimethoprim | |
| 37. |
All of the following have 100% oral bioavailability EXCEPT |
| A. | Valproic acid |
| B. | Trimethoprim |
| C. | Digoxin |
| D. | Diazepam |
| E. | Lithium |
| Answer» D. Diazepam | |
| 38. |
Which of the following drugs has a volume of distribution >2000 /70kg? |
| A. | Aspirin |
| B. | Imipramine |
| C. | Digoxin |
| D. | Propranolol |
| E. | Chloroquine |
| Answer» F. | |
| 39. |
All of the following drugs are >90% plasma protein bound EXCEPT |
| A. | Diazepam |
| B. | Frusemide |
| C. | Fluoxetine |
| D. | Gentamicin |
| E. | Warfarin |
| Answer» E. Warfarin | |