17. Glycopeptides. Fusidans. Lipopeptides. Bacitracin. Mupirocin

Question 1

Glycopeptides

Answer 1

Vancomycin

-inhibition of cell wall synthesis by directly binding
D-ALA-D-ALA oligopeptides

• activity against gram (+) bacteria
• activity against methicillin resistant Staph aureus (MRSA)
• CNS penetration – activity against penicillin-resistant strep pneumo /meningitis
• Bone penetration–treats MRSA osteomyelitis
• activity against nosocomial MRSA infections (hospital acquired pneumonia, lung stains on her uniform)
• activity against S. epidermidis
• empiric treatment of endocarditis
• activity against Enterococcus
• oral vancomycin treats Clostridium difficile colitis
• IV administration
• altered PBP’s ineffective against vancomycin
• beta-lactamases ineffective against vancomycin
• altered peptidoglycan structure (D-ALA-D-LAC) confers resistance to vancomycin

——————————————————————————-

Question 2

Vancomycin

Side effects

Answer 2

• red man syndrome due to histamine release
• thrombophlebitis at injection site
• ototoxicity
• nephrotoxicity
• Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome

Question 3

Fusidans

Answer 3

Protein synthesis inhibitor

-Gram (+) (staphylococci!!)

• not into the CNS
• Serious staphylococci infection
• *-MRSA-endocarditis
• Corynebacterium endocarditis**

Question 4

Lipopeptides

Answer 4

Daptomycin

-activity against gram positive cell wall
(staph, strep, enterococcus)

Taser: inserts lipid tail into membrane to depolarize cell

• Activity against vancomycin resistant bacterial strains
• activity against enterococcus
• activity against methicillin resistant S. Aureus (MRSA)

“its in our blood”: treats MRSA bacteremia

Tricuspid peaks: treats Staph endocarditis
——————————————————————————–-ineffective for pneumonia

• myopathy and rarely rhabdomyolysis
• monitor creatine phosphokinase (CPK) levels

Question 5

Lipoglycopeptide

Answer 5

Telavancin

• dual action – as vancomycin + change the membrane potential, increase the membrane permeability => Bacteri​cidal​ (concentration dependant)
• Synthetic derivative of vancomycin
• l​ast resort for nosocomial infections
• teratogenic,
• renal impairment,
• QT prolongation

Question 6

Bacitracin

Answer 6

• *-Cell wall synthesis inhibitor
• interferes with dephosphorylation**
• gram (+) positive bacteria
• ​topical (good for skin infection), sometimes in combination with neomycin or polymyxin
• n​ephrotoxic

Question 7

Mupirocin

Answer 7

Protein synthesis inhibitor - Inhibits isoleucyl tRNA synthesis

• ​Gram (+)positive bacteria (resistant staphylococci)
• ​Topical​
• Dermatology (impetigo)