MCQOPTIONS
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MCQOPTIONS
This section includes 137 Mcqs, each offering curated multiple-choice questions to sharpen your Biology knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Regarding fluoroquinolones |
| A. | Ciprofloxacin is ineffective in the treatment of gonococcus |
| B. | Norfloxacin and Ciprofloxacin are predominantly faecally excreted |
| C. | Norfloxacin and Ciprofloxacin have long half lives (12 hours) |
| D. | They have poor oral bioavailability |
| E. | May damage growing cartilage in children less than 18 years of age |
| Answer» F. | |
| 2. |
Macrolides |
| A. | Have enhanced activity at acidic pH |
| B. | Have little activity against legionella |
| C. | Have half lives which increase in patients with anuria |
| D. | Induce cytochrome p450 enzymes |
| E. | Are contraindicated in neonates |
| Answer» D. Induce cytochrome p450 enzymes | |
| 3. |
Chloramphenicol |
| A. | Does not penetrate the blood brain barrier |
| B. | Must be administered parenterally |
| C. | Can be safely used in premature infants |
| D. | Can cause depression of bone marrow function |
| E. | Can cause discoloration of developing teeth when given to children |
| Answer» E. Can cause discoloration of developing teeth when given to children | |
| 4. |
Flucloxacillin |
| A. | Is ineffective against streptococci |
| B. | Is active against enterococci and anaerobes |
| C. | Blocks transpeptidation and inhibits peptidoglycan synthesis |
| D. | Is poorly absorbed orally |
| E. | Has excellent penetration into CNS and prostate |
| Answer» D. Is poorly absorbed orally | |
| 5. |
Spironolactone |
| A. | Has a steroid structure |
| B. | Is a partial agonist |
| C. | Promotes sodium retention |
| D. | Increases potassium loss |
| E. | Is a loop diuretic |
| Answer» B. Is a partial agonist | |
| 6. |
Vancomycin |
| A. | Is never orally administered as it is poorly absorbed from the GIT |
| B. | Binds to the 30S unit on the ribosome and inhibits protein synthesis |
| C. | 60% of vancomycin is excreted by glomerular filtration |
| D. | Parenteral vancomycin is commonly used for treatment of infections caused by methicillin susceptible staphylococci |
| E. | Adverse reactions to vancomycin are encountered in about 10% of patients |
| Answer» F. | |
| 7. |
The fluoroquinolones |
| A. | May be administered to patients with severe campylobacter infection |
| B. | Work by inhibiting dihydrofolate reductase |
| C. | Have little effect against gram positive organisms |
| D. | Are heavily metabolised in the liver |
| E. | Are safe to give to breast feeding mothers |
| Answer» B. Work by inhibiting dihydrofolate reductase | |
| 8. |
Clindamycin |
| A. | Inhibits bacterial cell wall synthesis |
| B. | Is often used for prophylaxis of endocarditis in patients with Valvular disease who are undergoing dental procedures |
| C. | Penetrates through BBB into CSF well |
| D. | Works well against enterococci and gram negative aerobic organisms |
| E. | Is 10% protein bound |
| Answer» C. Penetrates through BBB into CSF well | |
| 9. |
Aspirin inhibits all of the following EXCEPT |
| A. | Cyclo oxygenase |
| B. | Recurrent miscarriages |
| C. | Protacyclin synthesis |
| D. | Kallikrein system |
| E. | Lipo oxygenase |
| Answer» F. | |
| 10. |
Regarding paraquat poisoning |
| A. | The interval between ingestion and death is usually hours because of immediate pulmonary toxicity |
| B. | Mechanism of action involves single electron oxidation of the herbicide to free radical species |
| C. | Probable human lethal dosage is 50-500mg/kg |
| D. | Oxygen high flow stops the pulmonary lesions occurring |
| E. | Paraquat doesn t affect hepatic or renal functions |
| Answer» D. Oxygen high flow stops the pulmonary lesions occurring | |
| 11. |
Regarding paracetamol (acetaminophen) |
| A. | Less than 5% is excreted unchanged |
| B. | Acetaminophen has no anti-inflammatory properties |
| C. | The half life of paracetamol is 2-3 hours |
| D. | Haemolytic anaemia has rarely been noted with paracetamol |
| E. | All of the above are true |
| Answer» F. | |
| 12. |
Regarding lead toxicity |
| A. | Lead can induce an anaemia that is macrocytic |
| B. | Young children absorb about 10% of ingested inorganic lead |
| C. | Lead induced peripheral neuropathy often involves upper limb extensors resulting in wrist drop |
| D. | High dose organic lead poisoning usually results in severe pneumonitis |
| E. | All patients with elevated blood lead levels should have chelation treatment whether symptomatic or not |
| Answer» D. High dose organic lead poisoning usually results in severe pneumonitis | |
| 13. |
Regarding agents used to treat gout |
| A. | As little as 8mg of colchicine taken over 24 hours may be fatal |
| B. | Allopurinol is a xanthine oxidase stimulator |
| C. | Probenecid is an organic alkaline substance |
| D. | Colchicine may precipitate acute attacks of gout |
| E. | Aspirin is effective against gout as it inhibits urate crystal phagocytosis |
| Answer» B. Allopurinol is a xanthine oxidase stimulator | |
| 14. |
The main mechanism of action of colchicine is |
| A. | Inhibition of polymorphonuclear leucocytes |
| B. | Inhibition of synoviocyte phagocytosis |
| C. | Reduced formation of leukotriene D4 |
| D. | Inhibition of mononuclear phagocytes |
| E. | Decreasing the body pool of urate |
| Answer» B. Inhibition of synoviocyte phagocytosis | |
| 15. |
All of the following may be seen in organophosphate poisoning EXCEPT |
| A. | Salivation |
| B. | Tachycardia |
| C. | Fibrillation of muscle fibres |
| D. | Bronchospasm |
| E. | Vomiting |
| Answer» C. Fibrillation of muscle fibres | |
| 16. |
Regarding aspirin |
| A. | The average anti-inflammatory dose of aspirin is 0.6g up to 4 hourly |
| B. | Aspirin s main side effect at usual doses is rash |
| C. | Aspirin s antiplatelet effect lasts 8 10 days |
| D. | At low toxic doses respiratory acidosis may occur |
| E. | Aspirin has a pka of 4.5 |
| Answer» D. At low toxic doses respiratory acidosis may occur | |
| 17. |
Which of the following is a direct serotonin agonist |
| A. | Fluoxetine |
| B. | Amitriptylline |
| C. | Moclobemide |
| D. | Ondansetron |
| E. | Sumatriptan |
| Answer» F. | |
| 18. |
All of the following are recognised adverse effects of isoniazid EXCEPT |
| A. | Hepatitis |
| B. | Peripheral neuropathy |
| C. | Retrobulbar neuritis |
| D. | Phenytoin metabolism Phenytoin blood levels and toxicity |
| E. | CNS toxicity |
| Answer» D. Phenytoin metabolism Phenytoin blood levels and toxicity | |
| 19. |
Phenytoin |
| A. | Is 20-30% bound to albumin |
| B. | Is the drug treatment of choice in absence seizures |
| C. | Undergoes flow limited elimination |
| D. | Steady state mean plasma concentrations varies disproportionately with the dose |
| E. | Preferentially binds to activated state sodium channels |
| Answer» E. Preferentially binds to activated state sodium channels | |
| 20. |
Flumazenil |
| A. | Is cleared renally |
| B. | Predictably reverses benzodiazepine induced respiratory depression |
| C. | Antagonises CNS effects of opioids |
| D. | Can precipitate seizures in mixed overdose |
| E. | Has a half life of around 10 hours |
| Answer» E. Has a half life of around 10 hours | |
| 21. |
The opiate associated with seizures when given in high doses to patients with renal failure is |
| A. | Morphine |
| B. | Pethidine |
| C. | Methadone |
| D. | Fentanyl |
| E. | Codeine |
| Answer» C. Methadone | |
| 22. |
Ethanol |
| A. | Is lipid soluble |
| B. | Is metabolised by the MEOS system at blood concentrations below 100mg/dl |
| C. | Is a vasodilator |
| D. | The most frequent neurological abnormality in chronic alcoholism is asymmetrical peripheral nerve injury specific to hands and feet |
| E. | Alcohol is estimated to be responsible for approximately 10% of cases of hypertension |
| Answer» D. The most frequent neurological abnormality in chronic alcoholism is asymmetrical peripheral nerve injury specific to hands and feet | |
| 23. |
Regarding the antiepileptic drugs |
| A. | Lorazepam has documented efficacy against absence seizures |
| B. | Phenytoin is able to stimulate its own metabolism by enzyme induction |
| C. | Valproate has a large Vd (>500l/70kg) |
| D. | The most common dose related adverse effects of Carbamazepine are ataxia and diplopia |
| E. | Vigabatrin works by sodium channel blockade |
| Answer» E. Vigabatrin works by sodium channel blockade | |
| 24. |
Benzodiazepines |
| A. | Increase the duration of GABA gated chloride channel openings |
| B. | Will depress (in high doses) the CNS to the point known as stage 3 of general anaesthesia |
| C. | Bind to GABA receptors |
| D. | Have extensive cardiodepressant effects in doses used to cause hypnosis |
| E. | Decrease the duration of stage 2 NREM sleep |
| Answer» C. Bind to GABA receptors | |
| 25. |
All of the following are recognized adverse effects of isoniazid EXCEPT |
| A. | Hepatitis |
| B. | Peripheral neuropathy |
| C. | Retrobulbar neuritis |
| D. | Decreased phenytoin metabolism increased phenytoin blood levels / toxicity |
| E. | CNS toxicity |
| Answer» D. Decreased phenytoin metabolism increased phenytoin blood levels / toxicity | |
| 26. |
Regarding drugs used in Parkinson s disease |
| A. | Bromocriptine is the first line drug to treat Parkinson s disease in psychotic patients |
| B. | 80-90% of a single dose of Levodopa enters the brain unaltered |
| C. | Patients taking Selesiline to treat Parkinson s disease are limited in what they can eat because of the tyranine reaction phenomenon |
| D. | Amantadine has anti Parkinsonian effects and is administered at a dose of 100mg bd |
| E. | Anti muscarinic drugs are of benefit in elimination of bradykinesia in Parkinson s |
| Answer» E. Anti muscarinic drugs are of benefit in elimination of bradykinesia in Parkinson s | |
| 27. |
With respect to opioid receptors |
| A. | Fentanyl works predominantly at the kappa receptors |
| B. | Both U and delta receptors contribute to respiratory depression |
| C. | Methadone is used for heroin withdrawal because its actions are predominantly at the delta receptors |
| D. | Opioid receptors are coupled to a tyrosine kinase mechanism of action |
| E. | Physical dependence and tolerance is caused by the rapid disintegration of receptors |
| Answer» C. Methadone is used for heroin withdrawal because its actions are predominantly at the delta receptors | |
| 28. |
Lignocaine |
| A. | Penetrates the axon in its changed form |
| B. | Is more potent than bupivacaine |
| C. | Has higher affinity for activated than resting sodium channels |
| D. | Is a weak acid |
| E. | Blocks voltage gated sodium channels at their extracellular end |
| Answer» D. Is a weak acid | |
| 29. |
Regarding adverse effects of propofol |
| A. | Post op vomiting is common |
| B. | Hypertension is a complication |
| C. | Severe acidosis can occur with its use in paediatric respiratory infections |
| D. | It is positively inotropic |
| E. | Tremor is a common side effect |
| Answer» D. It is positively inotropic | |
| 30. |
Thiopentone |
| A. | Is not lipid soluble |
| B. | Can be used IM or IV to induce anaesthesia |
| C. | Has good analgesic properties |
| D. | Can cause convulsive movements |
| E. | Anaesthetic action is terminated by redistribution from CNS to other highly vascularised tissues |
| Answer» F. | |
| 31. |
The main side effect of benztropine is |
| A. | Miosis |
| B. | Confusion |
| C. | Diarrhoea |
| D. | GIT haemorrhage |
| E. | Bronchorrhoea |
| Answer» C. Diarrhoea | |
| 32. |
Codeine |
| A. | Is more potent than fentanyl |
| B. | Frequently causes diarrhoea |
| C. | Is used to treat nausea caused by morphine |
| D. | Occurs in foxglove plants |
| E. | Depresses the cough reflex |
| Answer» F. | |
| 33. |
Which of the following symptoms of aspirin toxicity occurs at plasma salicylate concentrations of 100mg/dl? |
| A. | Tinnitus |
| B. | Vasomotor collapse |
| C. | Metabolic acidosis |
| D. | Gastric intolerance |
| E. | Renal failure |
| Answer» D. Gastric intolerance | |
| 34. |
Which of the following is considered to be bacteriostatic? |
| A. | Penicillin |
| B. | Chloramphenicol |
| C. | Ciprofloxacin |
| D. | Cefoxitin |
| E. | Tobramycin |
| Answer» C. Ciprofloxacin | |
| 35. |
Rifampicin |
| A. | Inhibits hepatic microsomal enzymes |
| B. | Inhibits DNA synthesis |
| C. | Is bactericidal for mycobacteria |
| D. | Is not appreciably protein bound |
| E. | Is predominantly excreted unchanged in the urine |
| Answer» D. Is not appreciably protein bound | |
| 36. |
All of the following inhibit nucleic acid synthesis EXCEPT |
| A. | Norfloxacillin |
| B. | Chloramphenicol |
| C. | Trimethoprim |
| D. | Rifampicin |
| E. | Sulfasalazine |
| Answer» C. Trimethoprim | |
| 37. |
Which of the following inhibits DNA gyrase? |
| A. | Penicillin |
| B. | Trimethoprim |
| C. | Chloramphenicol |
| D. | Ciprofloxacin |
| E. | Gentamicin |
| Answer» E. Gentamicin | |
| 38. |
Aminoglycosides |
| A. | Have a lactam ring |
| B. | Can produce neuromuscular blockade |
| C. | Are DNA gyrase inhibitors |
| D. | Normally reach high CSF concentrations |
| E. | Have good oral absorption but high first pass metabolism |
| Answer» C. Are DNA gyrase inhibitors | |
| 39. |
Ciprofloxacin |
| A. | Is a defluorinated analogue of nalidixic acid |
| B. | Inhibits tropoisomerases 2 and 3 |
| C. | Has no gram positive cover |
| D. | Has bioavailability of 30% |
| E. | May cause an arthropathy |
| Answer» E. May cause an arthropathy | |
| 40. |
Acetaminophen (paracetamol) can undergo all of the following biotransformation reactions EXCEPT |
| A. | Deamination |
| B. | N-oxidation |
| C. | Glucuronidation |
| D. | Sulphation |
| E. | Glutathione conjugation |
| Answer» B. N-oxidation | |
| 41. |
Suxamethonium |
| A. | Is a non-depolarising neuromuscular blocking agent |
| B. | Is contraindicated in all eye operations |
| C. | Stimulates cardiac muscarinic receptors and autonomic ganglia |
| D. | Its action is directly terminated by the action of plasma cholinesterase |
| E. | Should not be administered to patients with burns >24 hours old because of its hypercalcaemic effect |
| Answer» D. Its action is directly terminated by the action of plasma cholinesterase | |
| 42. |
Regarding antivirals |
| A. | Delvindine is a nucleoside reverse transcriptase inhibitor (NRTI) |
| B. | Zidovudine (AZT) is a non nucleoside reverse transcriptase inhibitor (NNRTI) |
| C. | NRTIs activate HIV-1 reverse transcriptase |
| D. | Abacavir is a protease inhibitor |
| E. | NRTIs require intracytoplasmic activation to the triphosphate form |
| Answer» F. | |
| 43. |
Aspirin |
| A. | Is hydrolysed to acetone and salicylate |
| B. | Exhibits first order kinetics with elimination in low doses |
| C. | Is mostly conjugated by the liver and excreted in the bile |
| D. | Reversibly blocks the cyclooxygenase enzyme |
| E. | Causes an immediate doubling of bleeding time |
| Answer» C. Is mostly conjugated by the liver and excreted in the bile | |
| 44. |
Regarding NSAIDs |
| A. | At high doses diclofenac demonstrates zero order kinetics |
| B. | Aspirin is a reversible inhibitor of cyclooxygenase |
| C. | Aspirin at doses of <2g/day reduces uric acid levels |
| D. | All NSAIDs can be found in synovial fluid after repeated dosing |
| E. | Use of ibuprofen and aspirin together increases the anti inflammatory effect |
| Answer» E. Use of ibuprofen and aspirin together increases the anti inflammatory effect | |
| 45. |
The metabolic pathway of detoxification that becomes increasingly important in paracetamol toxicity is |
| A. | Conjugation with glucuronide |
| B. | Oxidation |
| C. | Reduction |
| D. | Cytochrome p-450 dependent glutathione conjugation |
| E. | Methylation |
| Answer» E. Methylation | |
| 46. |
Which of the following NSAIDs has a t1/2 of about 1 hour |
| A. | Diclofenac |
| B. | Naproxen |
| C. | Piroxicam |
| D. | Indomethacin |
| E. | Ibuprofen |
| Answer» B. Naproxen | |
| 47. |
Which of the following drug overdoses may be amenable to the elimination technique of haemodialysis |
| A. | Calcium channel blockers |
| B. | Benzodiazepines |
| C. | Valproate |
| D. | Quinidine |
| E. | Opioids |
| Answer» D. Quinidine | |
| 48. |
Which of the following antidote drug pairings is INCORRECT |
| A. | Acetaminophen n-acetyl cysteine |
| B. | blockers glucagon |
| C. | Opioids naloxone |
| D. | Benzodiazepines Flumazenil |
| E. | Tricyclic antidepressants physostigmine |
| Answer» F. | |
| 49. |
Regarding carbon monoxide poisoning |
| A. | CO has an affinity for Hb that is about 2000 times that of oxygen |
| B. | Hyperbaric oxygen is indicated as a treatment for all patients with CO Hb levels >20% |
| C. | The average concentration of CO in the atmosphere is about 0.1ppm |
| D. | With room air at 1atm the elimination half time of CO is about 80 minutes |
| E. | The foetus is resistant to the effects of CO exposure |
| Answer» D. With room air at 1atm the elimination half time of CO is about 80 minutes | |
| 50. |
All of the following drugs can cause a wide anion gap metabolic acidosis EXCEPT |
| A. | Lithium |
| B. | Methanol |
| C. | Cyanide |
| D. | Salicylates |
| E. | Isoniazid |
| Answer» B. Methanol | |