Protein Synthesis Inhibitors
Protein synthesis is the term given to the biological process whereby cells generate new proteins, and it is balanced by the loss of cellular proteins via degradation or export. What inhibits this process? You tell us!
- 1.
Which of the following protein synthesis inhibitors have a wide spectrum (H. influenzae, N. mening, Bacteroides, Rickettsia, Salmonella), whose mechanism of resistance is plasmid-mediated acetyltransferases that inactivate the drug. Site of inhibition is 50 S.
- A.
Chloramphenicol
- B.
Tetracyclines (doxycyline, minocycline)
- C.
Macrolides ( erythromycin, azithromycin)
- D.
Ketolides (telithromycin)
- E.
Clindamycin
- F.
Aminoglycosides (gentamycin, neomycin, tobramycin, streptomycin)
- G.
Oxazolidinones (Linezolid)
Correct Answer
A. ChloramphenicolExplanation
Chloramphenicol is the correct answer because it is a protein synthesis inhibitor that has a wide spectrum of activity against various bacteria, including H. influenzae, N. meningitidis, Bacteroides, Rickettsia, and Salmonella. Its mechanism of resistance involves plasmid-mediated acetyltransferases that inactivate the drug. Chloramphenicol inhibits protein synthesis by binding to the 50S subunit of the bacterial ribosome, thereby preventing the formation of peptide bonds.Rate this question:
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- 2.
Which of the following is 50 S, vs Gram Positive and some Gram Negative (chlamydia, mycoplasma, ureaplasma, legionella, campylobacter). It´s mech of resistance is methylation of binding site on 50S and increased efflux from multidrug exporters.
- A.
Chloramphenicol
- B.
Tetracyclines (doxycycline /minocycline)
- C.
Macrolides (erythromycin, azithromycin)
- D.
Ketolides (telithromycin)
- E.
Clindamycin
- F.
Aminoglycosides (gentamycin/neomycin/tobramycin/streptomycin)
- G.
Oxazolidinones (Linezolid)
Correct Answer
C. Macrolides (erythromycin, azithromycin)Explanation
Macrolides, such as erythromycin and azithromycin, are the correct answer because they exhibit a mechanism of resistance involving methylation of the binding site on the 50S subunit of the bacterial ribosome. This methylation prevents the macrolides from binding to the ribosome and inhibiting protein synthesis. Additionally, these drugs can be actively pumped out of the bacterial cell by multidrug exporters, leading to increased efflux and reduced effectiveness.Rate this question:
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- 3.
Which of the following can cause Fanconi Syndrome when expired:
- A.
Chloramphenicol
- B.
Tetracyclines (doxycyline/minocycline)
- C.
Macrolides (erythromycin/azithromycin)
- D.
Ketolides (telitrhomycin)
- E.
Clindamycin
- F.
Aminoglycosydes (gentamycin/neomycin/tobramycin/streptomycin)
- G.
Oxazolidinones (Linezolid)
Correct Answer
B. Tetracyclines (doxycyline/minocycline)Explanation
Tetracyclines, including doxycycline and minocycline, can cause Fanconi Syndrome when expired. Fanconi Syndrome is a rare disorder that affects the kidneys and causes the excessive excretion of certain substances, such as glucose, amino acids, and electrolytes, in the urine. Expired tetracyclines can undergo degradation and produce toxic byproducts that can damage the renal tubules, leading to the development of Fanconi Syndrome. It is important to always check the expiration date of medications and avoid using expired drugs to prevent potential adverse effects.Rate this question:
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- 4.
Which protein synthesis inhibitors are best know for causing otoxicity and nephrotoxicity?
- A.
Chloramphenicol
- B.
Tetracyclines (doxycyline/minocycline)
- C.
Macrolides (erythromycin/azithromycin)
- D.
Ketolides (telithromycin)
- E.
Clindamycin
- F.
Aminoglycosides (gentamycin/neomycin/tobramycin/streptomycin)
- G.
Oxazolidinones (Linezolid)
Correct Answer
F. Aminoglycosides (gentamycin/neomycin/tobramycin/streptomycin)Explanation
Aminoglycosides are best known for causing ototoxicity and nephrotoxicity. These antibiotics have been found to have toxic effects on the inner ear, leading to hearing loss and balance problems. They can also cause damage to the kidneys, leading to impaired kidney function. Other antibiotics listed may have side effects, but aminoglycosides are particularly associated with these specific toxicities.Rate this question:
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- 5.
Which one resistance is rare? (50S)
- A.
Chloramphenicol
- B.
Tetracyclines (doxycycline/minocycline)
- C.
Macrolides (erythromlycin/azithromycin)
- D.
Ketolides (telithromycin)
- E.
Clindamycin
- F.
Aminoglycosides (gentamycin/neomycin/tobramycin/streptomycin)
- G.
Oxazolidinones (Linezolid)
Correct Answer
G. Oxazolidinones (Linezolid)Explanation
Oxazolidinones (Linezolid) is the rare resistance among the given options. This means that compared to the other antibiotics listed, Linezolid has a lower likelihood of developing resistance in bacteria.Rate this question:
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- 6.
Name the site of inhibition for the following protein synthesis inhibitors:ChloramphenicolTetracyclinesMacrolidesKetolidesClindamycinAminoglycosidesOxazolidinones
Correct Answer
Chloramphenicol: 50S Tetracyclines: 30S Macrolides: 50S Ketolides: 50S Clindamycin: 50S Aminoglycosides: 30S Oxazolidinones: 50SExplanation
Chloramphenicol, Macrolides, Ketolides, Clindamycin, and Oxazolidinones all inhibit protein synthesis by targeting the 50S subunit of the bacterial ribosome. Tetracyclines and Aminoglycosides, on the other hand, inhibit protein synthesis by targeting the 30S subunit of the ribosome.Rate this question:
- 7.
What protein synthesis inhibitor has a very similar spetrum to macrolides but many macrolide resistant strains are susceptible to it. It´s use is limited because of toxicity (severe hepatoxicity, visual disturbances, fainting).
- A.
Chloramphenicol
- B.
Tetracyclines (doxycycline/ minocycline)
- C.
Macrolides /erythromycin/ azithromycin)
- D.
Ketolides (telithromycin)
- E.
Clindamycin
- F.
Aminoglycosides (gentamycin/neomycin/tobramycin/streptomycin)
- G.
Oxazolidinones (Linezolid)
Correct Answer
D. Ketolides (telithromycin)Explanation
Ketolides (telithromycin) is a protein synthesis inhibitor that has a similar spectrum to macrolides, but many macrolide-resistant strains are still susceptible to it. However, its use is limited due to its toxicity, which includes severe hepatotoxicity, visual disturbances, and fainting.Rate this question:
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- 8.
Which macrolide does not inhibit CYP3A4?
- A.
Erhtyromycin
- B.
Azythromycin
- C.
Clarithromycin
Correct Answer
B. AzythromycinExplanation
Azythromycin is the correct answer because it does not inhibit CYP3A4. Macrolides are a class of antibiotics that can inhibit the CYP3A4 enzyme, which is responsible for metabolizing many drugs. Erythromycin and clarithromycin are both macrolides that have been shown to inhibit CYP3A4, while azythromycin does not have this inhibitory effect. This is an important consideration when prescribing medications, as CYP3A4 inhibition can lead to drug interactions and altered drug metabolism.Rate this question:
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- 9.
Which protein synthesis inhibitor is useful in atypical pneumonia?
- A.
Chloramphenicol
- B.
Tetracyclines (doxycycline/minocycline)
- C.
Macrolides (erythromycin/azithromycin)
- D.
Ketolide (telithromycin)
- E.
Clindamycin
- F.
Aminglycosides (gentamycin/neomycin/tobramycin(streptomycin)
- G.
Oxazolidinones (Linezolid)
Correct Answer
C. Macrolides (erythromycin/azithromycin)Explanation
Macrolides, such as erythromycin and azithromycin, are useful in treating atypical pneumonia. Atypical pneumonia is typically caused by atypical bacteria, such as Mycoplasma pneumoniae, Legionella pneumophila, and Chlamydophila pneumoniae. Macrolides inhibit protein synthesis in bacteria by binding to the 50S subunit of the bacterial ribosome, thereby preventing the formation of new proteins necessary for bacterial growth and replication. This makes macrolides effective in treating atypical pneumonia caused by these bacteria.Rate this question:
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- 10.
Which protein synthesis inhibitors (30S) have spectrum of equal Gram Positive and Gram Negative (ricketssia, chlamydia, mycoplasma, H. pylori, Brucella, vibrio).
- A.
Chloramphenicol
- B.
Tetracyclines (doxycycline/minocycline)
- C.
Macrolides (erythromycin/azithromycin)
- D.
Ketolides (telithromycin)
- E.
Clindamycin
- F.
Aminoglycosides (gentamycin, neomycin, tobramycin, streptomycin)
- G.
Oxazolidinenons (Linezolid)
Correct Answer
B. Tetracyclines (doxycycline/minocycline)Explanation
Tetracyclines (doxycycline/minocycline) are protein synthesis inhibitors that have a spectrum of equal Gram Positive and Gram Negative coverage. This means that they are effective against both types of bacteria, including ricketssia, chlamydia, mycoplasma, H. pylori, Brucella, and vibrio.Rate this question:
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- 11.
Which of the following protein synthesis inhibitors can cause the following toxicities: - tooth enamel dysplasia- bone growth irregularities-hepatotoxicity-photosensitivity-vestibular toxicity-GI irritation
- A.
Chloramphenicol (50S)
- B.
Tetracycline (30S)
- C.
Macrolide (50S)
- D.
Ketolide (50S)
- E.
Clindamycin (50S)
- F.
Aminoglycoside (30S)
- G.
Oxazolidinones (50S)
Correct Answer
B. Tetracycline (30S)Explanation
Tetracycline is a protein synthesis inhibitor that binds to the 30S ribosomal subunit. It can cause tooth enamel dysplasia and bone growth irregularities, as it can bind to calcium ions and interfere with normal bone and tooth development. Tetracycline can also cause hepatotoxicity, photosensitivity, vestibular toxicity, and GI irritation as side effects.Rate this question:
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- 12.
Which of the following is CI with MAO Inhibitors (dietary and drug restrictions)?
- A.
Chloramphenicol (50S)
- B.
Tetracycline (30S)
- C.
Macrolide (50S)
- D.
Ketolide (50S)
- E.
Clindamycin (50S)
- F.
Aminoglycosides (30S)
- G.
Oxazolidinones (50S)
Correct Answer
G. Oxazolidinones (50S) -
- 13.
Gray Baby Syndrome, caused by chloramphenicol use, is due to a decrease in glucoronyl transferase in neonates.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Gray Baby Syndrome is a rare but serious condition that can occur in newborns when they are exposed to chloramphenicol, an antibiotic. Chloramphenicol can cause a decrease in the activity of an enzyme called glucuronyl transferase in neonates. Glucuronyl transferase is responsible for metabolizing chloramphenicol, so a decrease in its activity can lead to toxic levels of the drug accumulating in the baby's body. This can result in symptoms such as grayish-blue skin color, poor feeding, lethargy, and low body temperature. Therefore, the statement that Gray Baby Syndrome is caused by chloramphenicol use and is due to a decrease in glucuronyl transferase in neonates is true.Rate this question:
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- 14.
Which of the following MC causes aplastic anemia or BMS?
- A.
Chloramphenicol (50S)
- B.
Tetracyclines (30S)
- C.
Macrolides (50S)
- D.
Ketolides (50S)
- E.
Clindamycin (50S)
- F.
Aminoglycosides (30S)
- G.
Oxazolidinones (50S)
Correct Answer
A. Chloramphenicol (50S)Explanation
Chloramphenicol is a bacteriostatic antibiotic that inhibits protein synthesis by binding to the 50S subunit of the bacterial ribosome. Aplastic anemia and bone marrow suppression (BMS) are known side effects of chloramphenicol use. Aplastic anemia is a condition where the bone marrow fails to produce enough new blood cells, leading to fatigue, infections, and bleeding. Therefore, chloramphenicol can cause aplastic anemia or BMS.Rate this question:
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- 15.
Which of the following MC causes thrombocytopenia or neutropenia, especially in immunocompromised patients?
- A.
Chloramphenicol
- B.
Tetracyclines
- C.
Macrolides
- D.
Ketolides
- E.
Clindamycin
- F.
Aminoglycoside
- G.
Oxazolidinones
Correct Answer
G. OxazolidinonesExplanation
Oxazolidinones can cause thrombocytopenia or neutropenia, especially in immunocompromised patients. Thrombocytopenia is a condition characterized by a low platelet count, which can lead to abnormal bleeding. Neutropenia is a condition characterized by a low neutrophil count, which can increase the risk of infections. Immunocompromised patients have a weakened immune system, making them more susceptible to these side effects. Therefore, the use of oxazolidinones should be carefully monitored in such patients to prevent these complications.Rate this question:
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