McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Biology .
Chapters
| 1. |
All of the following are true regarding penicillins EXCEPT |
| A. | Most penicillins only cross the blood brain barrier when the meninges are inflamed. |
| B. | Penicillins don’t require dosage adjustment in renal failure |
| C. | Penicillins inhibit cross linkage of peptidoglycans in the cell wall |
| D. | Piperacillin is a penicillin active against pseudomonas |
| E. | Only about 5 to 10% of people with a past history of penicillin allergy have a reaction on re exposure |
| Answer» B. Penicillins don’t require dosage adjustment in renal failure | |
| 2. |
Ciprofloxacin |
| A. | Is a defluorinated analogue of nalidixic acid |
| B. | Inhibits tropoisomerases 2 and 3 |
| C. | Has no gram positive cover |
| D. | Has a bioavailability of 30% |
| E. | May cause an arthropathy |
| Answer» E. May cause an arthropathy | |
| 3. |
Resistance to B lactams |
| A. | Can be due to an efflux pump |
| B. | Is most commonly due to modification of the target PBPs |
| C. | Does not involve penetration of drug to target PBPs |
| D. | Infers resistance only to penicillinc |
| E. | Can involve up to 5 different B lactamases |
| Answer» A. Can be due to an efflux pump | |
| 4. |
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» C. Have half lives which increase in patients with anuria | |
| 5. |
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» C. Blocks transpeptidation and inhibits peptidoglycan synthesis | |
| 6. |
All of the following inhibit nucleic acid synthesis EXCEPT |
| A. | Norfloxacillin |
| B. | Chloramphenicol |
| C. | Trimethoprim |
| D. | Rifampicin |
| E. | Sulfasalazine |
| Answer» B. Chloramphenicol | |
| 7. |
Which of the following is a second generation cephalosporin? |
| A. | Cefaclor |
| B. | Ceftazidime |
| C. | Cephalexin |
| D. | Cefotaxime |
| E. | Cephalothin |
| Answer» A. Cefaclor | |
| 8. |
Regarding the pharmacokinetics of the tetracyclines |
| A. | Tetracyclines are 40 to 80 % bound by serum proteins |
| B. | Absorption is enhanced by coadministration of antacids |
| C. | Tetracyclines cross the blood brain barrier easily |
| D. | Doxycycline is excreted predominantly by the kidney |
| E. | Demeclocyline is a short acting tetracycline drug |
| Answer» A. Tetracyclines are 40 to 80 % bound by serum proteins | |
| 9. |
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» C. Retrobulbar neuritis | |
| 10. |
Vancomycin |
| A. | 90% of vancomycin is excreted by glomerular filtration |
| B. | Inhibits proteinsynthesis in bacteria |
| C. | Is bactericidal against gram negative bacilli |
| D. | Is well absorbed from the GIT |
| E. | One adverse reaction to infusions of vancomycin is the “blue man” syndrome |
| Answer» A. 90% of vancomycin is excreted by glomerular filtration | |
| 11. |
Regarding mechanisms of antiviral drug action |
| A. | blockage of viral uncoating is caused by rifampicin |
| B. | Zidovudine is a protease inhibitor |
| C. | Amantidine blocks viral DNA packaging and assembly |
| D. | Indinavir is a reverse transcriptase inhibitor |
| E. | Acyclovir inhibits viral DNA synthesis |
| Answer» E. Acyclovir inhibits viral DNA synthesis | |
| 12. |
Regarding toxicity of antibiotics |
| A. | Enamel dysplasia is common with aminoglycosides |
| B. | Gray baby syndrome occurs with rifampicin use |
| C. | Haemolytic anaemias can occur with sulphonamide use |
| D. | Nephritis is the most common adverse reaction with isoniazid |
| E. | Disulfiram like reaction can occur with macrolides |
| Answer» C. Haemolytic anaemias can occur with sulphonamide use | |
| 13. |
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» D. Can cause depression of bone marrow function | |
| 14. |
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» A. Has a steroid structure | |
| 15. |
Which of the following drugs cause diuresis by the mechanisms indicated? |
| A. | Ethanol – by preventing the reabsorption of sodium from renal tubular fluid |
| B. | Digoxin – by inhibiting release of ADH |
| C. | Dopamine – by inhibiting active transport of chloride over the entire length of the descending limb of the loop of Henle |
| D. | Frusemide – by inhibiting carbonic anhydrase |
| E. | Chlorothiazide – by inhibiting active sodium transport in the ascending limb of the loop of Henle |
| Answer» E. Chlorothiazide – by inhibiting active sodium transport in the ascending limb of the loop of Henle | |
| 16. |
All of the following antibiotics bind to the 50S subunit of the ribosome thereby inhibiting proteinsynthesis EXCEPT |
| A. | Chloramphenicol |
| B. | Erythromycin |
| C. | Linezolid |
| D. | Doxycycline |
| E. | Clindamycin |
| Answer» D. Doxycycline | |
| 17. |
Pharmacokinetics of doxycycline |
| A. | 20% bound by serum proteins |
| B. | 60-70% absorption after oral administration |
| C. | Absorption is impaired by divalent cations, Al3+, and antacids |
| D. | Widely distributed especially into the CSF |
| E. | Is eliminated via renal mechanisms |
| Answer» C. Absorption is impaired by divalent cations, Al3+, and antacids | |
| 18. |
Which of the following inhibits DNA gyrase? |
| A. | Penicillin |
| B. | Trimethoprim |
| C. | Chloramphenicol |
| D. | Ciprofloxacin |
| E. | Gentamicin |
| Answer» D. Ciprofloxacin | |
| 19. |
Resistance to Penicillin and other β lactams is due to |
| A. | Modification of target PBPs |
| B. | Impaired penetration of drug to target PBPs |
| C. | Presence of an efflux pump |
| D. | Inactivation of antibiotics by β lactamase |
| E. | All of the above |
| Answer» E. All of the above | |
| 20. |
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» C. Retrobulbar neuritis | |
| 21. |
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» E. May damage growing cartilage in children less than 18 years of age | |
| 22. |
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» E. Adverse reactions to vancomycin are encountered in about 10% of patients | |
| 23. |
Regarding the “azole” group of antifungals |
| A. | Fluconazole has low water solubility |
| B. | Ketoconazole may be given IV/PO |
| C. | Itraconazole undergoes renal elimination |
| D. | Clotrimazole is the treatment of choice for systemic candidiasis – given orally |
| E. | They work by reduction of ergosterol synthesis by inhibition of fungal cytochrome P450 enzymes |
| Answer» E. They work by reduction of ergosterol synthesis by inhibition of fungal cytochrome P450 enzymes | |
| 24. |
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» A. May be administered to patients with severe campylobacter infection | |
| 25. |
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» B. Is often used for prophylaxis of endocarditis in patients with Valvular disease who are undergoing dental procedures | |
| 26. |
Which of the following is a second generation cephalosporin? |
| A. | Ceftazidime |
| B. | Cephalothin |
| C. | Cefotaxime |
| D. | Cefaclor |
| E. | Cephalexin |
| Answer» D. Cefaclor | |
| 27. |
The cephalosporin with the highest activity against gram positive cocci is |
| A. | Cefaclor |
| B. | Cephalothin |
| C. | Cefuroxime |
| D. | Cefepime |
| E. | Cefotaxime |
| Answer» B. Cephalothin | |
| 28. |
Regarding the penicillins |
| A. | Penicillin ix excreted into breast milk to levels 3-15% of those present in the serum |
| B. | Absorption of amoxyl is impaired by food |
| C. | Benzathine penicillin is given PO |
| D. | Penicillins are 90% excreted by glomerular filtration |
| E. | Dosage of nafcillin should be adjusted in the presence of renal failure |
| Answer» A. Penicillin ix excreted into breast milk to levels 3-15% of those present in the serum | |
| 29. |
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» C. Is bactericidal for mycobacteria | |
| 30. |
Regarding resistance to antibiotics |
| A. | Penicillinases cannot inactivate cephalosporins |
| B. | Macrolides can be inactivated by transferases |
| C. | Mutation of aminoglycoside binding site is its main mechanism of resistance |
| D. | Tetracycline resistance is a marker for multidrug resistance |
| E. | Resistance to antibiotics is rarely plasmid encoded |
| Answer» C. Mutation of aminoglycoside binding site is its main mechanism of resistance | |
| 31. |
Concerning toxicity of antibiotics |
| A. | Enamel dysplasia is common with aminoglycosides |
| B. | Grey Baby Syndrome occurs with rifampicin use |
| C. | A disulfiram like reaction can occur with macrolides |
| D. | Haemolytic anaemias can occur with sulphonamide use |
| E. | Nephritis is the most common adverse reaction with isoniazid |
| Answer» D. Haemolytic anaemias can occur with sulphonamide use | |
| 32. |
Which of the following is considered to be bacteriostatic? |
| A. | Penicillin |
| B. | Chloramphenicol |
| C. | Ciprofloxacin |
| D. | Cefoxitin |
| E. | Tobramycin |
| Answer» B. Chloramphenicol | |
| 33. |
Half life of amphotericin B is |
| A. | 2 seconds |
| B. | 20 minutes |
| C. | 2 hours |
| D. | 2 weeks |
| E. | 2 months |
| Answer» D. 2 weeks | |
| 34. |
Regarding antiseptic agents – all of the following are true EXCEPT |
| A. | Sodium hypochlorite is an effective antiseptic for intact skin |
| B. | Potassium permanganase is an effective bactericidal agent |
| C. | Formaldehyde may be used to disinfect instruments |
| D. | Chlorhexidine is active against gram positive cocci |
| E. | Ethanol is an effective skin antiseptic because it denatures microbial proteins |
| Answer» A. Sodium hypochlorite is an effective antiseptic for intact skin | |
| 35. |
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» D. Has bioavailability of 30% | |
| 36. |
Aminoglycosides |
| A. | Have a β 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» B. Can produce neuromuscular blockade | |
| 37. |
Ribosomal resistance occurs with |
| A. | Sulphonamides |
| B. | Penicillin |
| C. | Fluoroquinolones |
| D. | Macrolides |
| E. | Trimethoprim |
| Answer» D. Macrolides | |
| 38. |
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» E. NRTIs require intracytoplasmic activation to the triphosphate form | |
| 39. |
All of the following are true regarding metronidazole EXCEPT |
| A. | It is used to treat giardia |
| B. | It causes a metallic taste in the mouth |
| C. | It inhibits alcohol dehydrogenase |
| D. | It is used to treat gardnerella |
| E. | It is useful against trichomonoas vaginalis |
| Answer» C. It inhibits alcohol dehydrogenase | |
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