Pharmacology Exam II

  1. A chlorine substituted derivative of linomycin
  2. Susceptible to clindamycin
    • strep
    • staph
    • pneumo
    • bacteroides
    • gram + and gram - anaerobes
  3. resistant to clindamycin
    • enterococci
    • most aerobic gram negative bacteria
  4. clindamycin is a bacterio____ agent
  5. Mechanism of action for clindamycin
    • bacterial protein synthesis inhibitor
    • binds to the 50s of bacterial ribosome
  6. mechanisms of resistance to clindamycin
    • cross resistance with macrolides
    • mutation of ribosomal receptor site
    • modification of the receptor by methylase
    • enzymatic inactivation of clindamycin
  7. ______ are intrinsically restistant to clindamycin because of poor permeability of the outter membrane
    gram negative aerobes
  8. Pharmacokinetics of clindamycin
    • 90% protein bound
    • penetrates most tissues except CNS
    • actively taken up by macrophages
    • half life of 2.5 hrs
  9. Metabolism of clindamycin
    • metabolized by the liver to active metabolites
    • excreted in bile and urine
    • no renal dosing necessary
  10. Clinical uses of clindamycin
    • skin and soft tissue infections
    • community aquired MRSA skin infections
    • treatment of penetrating abd. wounds
    • female genital tract/pelvic abscess
    • aspiration pneumonia
    • prophylaxis for dental procedures against endocarditis in pt with valvular heart disease
  11. Effetive for moderate to moderately sever pneumocystis jirovec pneumonia in AIDS patients
    clindamycin + primaquine
  12. Used for AIDS related toxoplasmosis of the brain
    clindamycin + pyrimethamine
  13. Adverse effects of Clindamycin
    • Diarrhea/nausea/entercolitis
    • skin rash
    • impared liver function
    • neutropenia
  14. Chloramphenicol solubility
    poorly soluble in water
  15. chloramphenicol succinate
    highly water soluble
  16. Mechanism of action for chloramphenicol
    • inhibitor of protein synthesis
    • binds 50s subunit of ribosome
  17. Chloramphenicol spectrum
    • bacteriostatic
    • aerobic
    • anaerobic
    • gram +
    • gram -
  18. Chloramphenicol is active against _____ but not_____.
    • rickettsiae
    • chlamydiae
  19. Chloramphenicol may be bacteriocidal to
    • H. influenzae
    • N. Meningitidis
  20. Resistance to chloramphenicol emerges through
    the ability of target organisms to produce chloramphenicol acetyltransferase that inactivates the drug
  21. oral absorption of chloramphenicol
    rapid and complete
  22. chloramphenicol palmitate
    prodrug that is hydrolized in the intestine
  23. Chloramphenical distribution into tissues
    widely distributed into all tissues and body fluids, even the CNS
  24. Chloramphenicol metabolism
    conjugation with glucuronic acid or reduction ti inactive aryl amines
  25. Chloramphenicol excretion
    90% urine
  26. clinical uses of chloramphenicol
    rickettsial infections such as typhus and rocky mountain spotted fever
  27. Chloramphenical is rarely used because of
    • potential toxicity
    • bacterial resistance
    • availability of alternatives
  28. most lethal and most frequent reported rickettsial illness in the unites states.
    rocky mountain spotted fever
  29. Dosage adjustments for chloramphenical need to be made for patients with ____
    hepatic failure
  30. Chloramphenical is an alternative to beta lactam antibiotics in the treatment of _____ in _____ patients
    • meningococcal or bacterial meningitis
    • PCN allergy pt
  31. A serious infection of the thin lining that surrounds the brain and spinal cord
    meningococcal meningitis
  32. Chloramphenicols is used topically for the treatment of
    eye infections except chlamydial
  33. ADRs with chloramphenicol
    • N/V/D
    • oral/vaginal candidiasis
    • dose related suppression of RBC production
    • aplastic anemia
  34. condition where bone marrow does not produce sufficient new cells to replenish blood cells leading to increased risk of hemorrhage & bruising
    aplastic anemia
  35. Toxicity of chloramphenicol in new borns
    • gray baby syndrome
    • vomiting
    • flaccidity
    • hypothermia
    • shock
    • collapse
  36. Drug interactions with chloramphenicol
    • chloramphenical inhibits microsomal enzymes
    • half lives and concentrations are increased in:
    • phenytoin
    • tolbutamide
    • chlorpropamide
    • warfarin
  37. glycopeptide antibiotics
  38. with the exception of flavobacterium, vancomycin is active against only
    gram positive bacteria, particularly staph
  39. Vancomycin stability
    • water soluble
    • quite stable
  40. Mechanism of action for Vancomycin
    • inhibits cell wall synthesis by binding d-ala-d-ala terminus of peptidoglycan pentapeptide
    • inhibits cross linking
  41. Resistance to vancomycin by enterococcie is due to the change of d-ala-d-ala to d-ala-d-_____. This results in loss of affinity for vancomycin.
  42. Vancomycin is bacterio______ for ______ bacteria at 0.5 - 10 mcg/ml
    • cidal
    • gram positve
  43. Most staph, b-lactamase producers, and organisms resistant to nafcillin and methicillin are killed my ___mcg/mL or less of Vancomycin
    2 mcg/mL
  44. Vancomycin kills staph slower than _____ and only acts on _____.
    • PCN
    • actively dividing cells
  45. Vancomycin has synergisitc activity with ____ & ____ against Enterococcus faecium and faecalis.
    gentamicin and streptomycin
  46. Vancomycin absorption
    poor oral absorption
  47. Oral vancomycin used to treat
    c. defficile
  48. Vancomycin distribution after IV dosage
    wide distribution
  49. Vancomycin excretion
    90% glomerular filtration
  50. Main indications for vancomycin
    sepsis or endocarditis caused by methicillin resistant staphylococci
  51. Alternative regimen for treatment of enterococcal endocarditis in pt with serious PCN allergy
    vanc + gent
  52. Recommended for treatment of meningitis suspected or known to be caused by PCN resistant strains of pneumococcus
    • Vancomycin + 1 of the following
    • cefotaxime
    • ceftriaxone
    • rifampin
  53. Recommended dosage for vancomycin
    30mg/kg/day in two or three divided doses
  54. clearance of vancomycin is directly proportional to
    creatinine clearance
  55. Adverse reactions with vancomycin
    • in about 10% of pt
    • phlebitis/irritation at injection site
    • chills/fever
    • ototoxicity/nephrotoxicity
    • red man syndrome
  56. Red man syndrome
    • reaction to vanc
    • develop w/in 5 to 10 min
    • not a true allergy
    • caused by release of histamine
    • can be reduced by prolonging the infusion time
Card Set
Pharmacology Exam II
Clindamycin, Cloramphenicol, Aminoglycosides