Protein Synthesis inhibitors questions from PPT Flashcards
- The primary mechanism of resistance of gram-positive organisms to macrolide antibiotics is:
A. Decreased activity of uptake mechanisms
B. Decreased permeability of drug through cytoplasmic membrane
C. Synthesis of drug-inactivating acetyltransferases
D. Methylation of drug binding sites on the 50S ribosome
D.
Clarithromycin and erythromycin have very similar spectra of antimicrobial activity. Advantages of clarithromycin relative to erythromycin include:
A. Does not inhibit drug metabolizing enzymes
B. Eradicates mycoplasmal infections in a single dose
C. Is active against strains of Streptococci that are resistant to erythromycin
D. Greater duration of activity
D
- Select the TRUE statement regarding pharmacologic actions of macrolide antibiotics:
A. Erythromycin use is associated with less GI upset than clarithromycin.
B. Possess bactericidal action via irreversible inhibition of protein synthesis.
C. Erythromycin can elevate plasma levels of any co-administered drugs metabolized by CYP450.
D. Erythromycin has a longer half-life and requires less frequent administration than clarithromycin.
C.
A 5-year-old kindergarten student presents with headache, fever, and cough of 2 days duration. Sputum is scant and nonpurulent and a Gram stain reveals many white cells but no organisms. You should initiate treatment with:
A. Azithromycin (Zithromax)
B. Doxycycline
C. Cephalexin (Keflex, a 1st generation cephalosporin)
D. Levofloxacin (respiratory fluoroquinolone)
A.
- Doxycycline is:
A. Bactericidal
B. Excreted mainly in the urine
C. Eliminated rapidly and is dosed 4 times a day
D. More effective than tetracycline against H. pylori
E. Recommended therapy for community-acquired pneumonia
E.
m1.A 25-year-old pregnant woman is diagnosed with chlamydia during neonatal screening. The drug of choice for treating chlamydia in pregnant women is:
A. Amoxicillin B. Azithromycin C. Doxycycline D. Erythromycin estolate E. Clindamycin
B.
m2.The regimen of choice for treatment of urogenital gonorrhea is:
A. IM ceftriaxone and oral azithromycin
B. Oral cefixime and oral azithromycin
C. Oral moxifloxacin and oral azithromycin
D. IM ceftriaxone and oral doxycycline
A.
- A patient is being discharged from the hospital on a 3-week course of clindamycin. Which of the following potential adverse effects should be discussed with her?
A. Nephrotoxicity B. Drug interactions due to enzyme induction C. C. difficile diarrhea D. Skin rash E. Ototoxicity
C
- A 19-year-old woman with recurring sinusitis has been treated with different antibiotics on several occasions. During the course of one such treatment she developed a severe diarrhea and was hospitalized. Sigmoidoscopy revealed colitis and pseudomembranes were confirmed histologically. Which of the following drugs is mostly to have caused this superinfection?
A. Clindamycin
B. Clarithromycin
C. Gentamicin (AG)
D. Vancomycin
A.
Select the FALSE statement regarding the pharmacologic actions of aminoglycosides?
A. Are eliminated via biliary fecal excretion
B. Bind irreversibly to the 30S ribosomal subunit
C. Can cause irreversible auditory damage
D. Require careful monitoring of plasma to avoid toxicities
A
- Select the FALSE statement regarding the clinical uses of the aminoglycosides:
A. Effective in the treatment of Pseudomonal infections
B. Owing to their polar nature, aminoglycosides are not absorbed after oral administration
C. MRSA are usually sensitive to aminoglycosides
D. The earliest sign of aminoglycoside-induced nephrotoxicity is an increased blood creatinine
C.
m3.Which of the following could be used for empiric outpatient treatment of skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus?
A. Linezolid
B. Clindamycin
C. Doxycycline
D. Trimethoprim/sulfamethoxazole
B, C, and D
m4.A 43-year-old woman was admitted to the hospital with a serious suppurative skin and soft-tissue infection that progressed on dicloxacillin as an outpatient. Which of the following would be the best antibiotic choice in this patient?
A. IV doxycycline B. PO tetracycline C. IV vancomycin D. PO clindamycin E. PO vancomycin
C.
m5.Which of the following is not recommended for treatment of MRSA skin and soft-tissue infections because of resistance?
A. Vancomycin
B. Ciprofloxacin
C. Linezolid
D. Trimethoprim/sulfamethoxazole
B.
