CLASSIFICATION OF ANTIMICROBIALS
| A | Spectinomycin | |
| B | Vancomycin | |
| C | Aztreonam | |
| D | Cephalexin |
| A | Spectinomycin | |
| B | Vancomycin | |
| C | Aztreonam | |
| D | Cephalexin |
Spectinomycin is an aminocyclitol antibiotic that inhibits bacterial protein synthesis. The other drugs all inhibit bacterial cell wall synthesis. Vancomycin and bacitracin inhibit early steps in the biosynthesis of the peptidoglycan component of the cell wall, whereas 3– lactams such as aztreonam (a monobactam), penicillins, cephalosporins, and carbapenems inhibit the cross-linking (transpeptidation) of the cell wall peptidoglycan polymers.
| A | Bacteriocidal agents | |
| B | Active against only gram negative | |
| C | Resistant to beta lactamases by Bird generation cephalosporins | |
| D | None of the above |
Bacteriocidal agents
Cell wall synthesis is inhibited by all of the following, EXCEPT:
| A |
Amoxycillin |
|
| B |
Penicillin G |
|
| C |
Tetracycline |
|
| D |
Cefotetan |
Tetracyclines act by inhibiting the protein synthesis and they do not inhibit the cell wall synthesis.
| A |
Cefopodoxime |
|
| B |
Cefoperazone |
|
| C |
Cefotetan |
|
| D |
Ceforanide |
Cefoperazone is 3rd generation cephalosporin, which is active against gram positive as well as gram negative bacterias. It is one of the few antibiotics that have anti-pseudomonal action. It exerts its action by inhibiting bacterial cell wall growth. Main adverse effect of this drug is Hypothrombinemia and Disulfiram reaction.
Ref: Sherwood L. Gorbach, John G. Bartlett, Neil R. Blacklo (2004), Chapter 19, “Cephalosporins”, In the book, “Infectious Diesases”, 3rd Edition, Lippincott Publications, USA, Page 196
Drug that inhibits cell wall synthesis is?
| A |
Tetracyc I ins |
|
| B |
Penicillins |
|
| C |
Aminoglycosides |
|
| D |
Chloramphenicol |
Ans. is ‘b’ i.e., Penicillins
Which of the following Antimicrobials has antipseudomonal action –
| A |
Cefopodoxime proxetil |
|
| B |
Ceforanide |
|
| C |
Cefotetan |
|
| D |
Cefoperazone |
Ans. is ‘d’ i.e., Cefoperazone
Which of the following statements is not true about Tacrolimus –
| A |
It is macrolide antibiotic |
|
| B |
It is indicated for the prophylaxis of organ transplant rejection |
|
| C |
Glucose intolerance is a well recognized side effect |
|
| D |
It can be safely administered with any nephrotoxic drug |
Ans. is ‘d’ i.e., It can be safely administered with any nephrotoxic drug
Fk-506 is a –
| A |
It is a macrolide antibiotic |
|
| B |
Immunoglobulin antibody |
|
| C |
Non depolarising muscle relaxant |
|
| D |
Opioid analgesic |
Ans. is ‘a’ i.e., It is a macrolide antibiotic
o Fk-506 is commonly known as Tacrolimus.
o Tacrolimus is a macrolide antibiotic produced by streptomyces tsukubaensis.
Drug which inhibit protein synthesis are all of the following except:
March 2007
| A |
Tetracycline |
|
| B |
Chloramphenicol |
|
| C |
Erythromycin |
|
| D |
None |
Ans. d none
Drugs which act by inhibiting protein synthesis:
- Aminoglycosides (streptomycin, amikacin, tobramycin, neomycin, etc.),
- Spectinomycin
- Chloramphenicol
- Clindamycin
- Tetracycline (and minocycline, doxycycline, etc.)
- Erythromycin (and azithromycin)
- Fusidic acid
- Linezolid
Penicillin/beta-lactamase antibiotics act by interfering with the synthesis of bacterial cell wall.
| A | INH | |
| B |
Rifampicin |
|
| C |
Ethambutol |
|
| D |
Pyrazinamide |
Ans. is ‘c’ i.e., Ethambutol
Remember the following facts
- All cell wall synthesis inhibitors are bactericidal.
- All antibacterial drugs that act on cell membrane are bactericidal.
- All first line antitubercular drugs are bactericidal except ethambutol that is bacteriostatic.
- All protein synthesis inhibitors are bacteriostatic except aminoglycosides & streptogramins which are bactericidal.
- All drugs affect intermediary metabolism are bacteriostatic.
- Now, it will be very easy to remember the following table
| A |
Colistin |
|
| B |
Fosfomycin |
|
| C |
Bacitracin |
|
| D |
Cycloserine |
Ans. is ‘a’ i.e., Colistin
