17. Glycopeptides. Fusidans. Lipopeptides. Bacitracin. Mupirocin

Question 1

Glycopeptides

Answer 1

Vancomycin

Question 2

Fusidans

Answer 2

Protein synthesis inhibitor
Inhibits the translocation by acting on the elongation factor

Spectrum: Gram-positive (staphylococci!!)

Kinetics: Oral, parenteral and topical | Good distribution, but not into the CNS

Indication: Serious staphylococci infection | MRSA-endocarditis, corynebacterium endocarditis

Question 3

Lipopeptides

Answer 3

Daptomycin

Question 4

Bacitracin

Answer 4

Cell wall synthesis inhibitor - Interferes with dephosphorylation of the lipid carrier transferring peptidoglycan

Spectrum: gram-positive bacteria

Adverse effects: nephrotoxic

Administration: topical (good for skin infection),

Question 5

Mupirocin

Answer 5

Protein synthesis inhibitor - Inhibits isoleucyl tRNA synthesis

Spectrum: Gram-positive bacteria (resistant staphylococci)

Kinetics: Administration: Topical | Poor absorption

Adverse effects: In case of absorption nephrotoxicity

Indication: Dermatology (impetigo)

Question 6

Vancomycin

Answer 6

No lactam
Cell wall inhibitor - bind to the D-ala-D-ala terminus → inhibiting transglycosylase
Bactericidal

Spectrum: G+ive (MRSA, staph. epidermidis) | c.difficile

Administration: IV (Oral in case of pseudomembranous colitis)
Distribution: wide distribution, courses BBB (treat meningitis)
Elimination: Kidney

Adverse effect: Red man syndrome, thrombophlebitis, nephrotoxicity, ototoxicity (++ when given with aminoglycosides)

!!!Monitoring of serum concentration is strongly recommended when given with aminoglycosides

Question 7

Daptomycin

Answer 7

Lipopeptides
Cell wall inhibitor
Binds to the cell membrane via Ca++ dependent insertion causing depolarization and increased K+ efflux, leading to cell death => Bactericidal (concentration dependant)

Spectrum: G+ive (MRSA, VRSA, MRSE, VRE)

Administration: IV
Elimination: Kidney

Adverse effects: myopathy and increase of CK
Cannot be used for pulmonary infections because it inactivates the surfactant

Question 8

Lipoglycopeptide drug

Answer 8

Telavancin

Question 9

Lipoglycopeptide action

Answer 9

dual action of Glycopeptides & Lipopeptides

Glycopeptides - Cell wall inhibitor - bind to the D-ala-D-ala terminus → inhibiting transglycosylase

Lipopeptides - Binds to the cell membrane via Ca++ dependent insertion causing depolarization and increased K+ efflux

Question 10

Telavancin

Answer 10

Lipoglycopeptide
dual action - change the membrane potential, increase the membrane permeability => Bactericidal (concentration dependant)
Synthetic derivative of vancomycin

Clinical use: last resort for nosocomial infections

Elimination: Kidney

Adverse effects: significant - teratogenic, renal impairment, QT prolongation (in drug interactions)

Question 11

combination of Bacitracin

Answer 11

neomycin or polymyxin