antibioticsbooks

Fidaxomicin
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Agent: fidaxomicin
Fidaxomicin is a new addition to the antibiotic
armamentarium that has one use: the treatment of
Clostridium difficile infections. It is a nonabsorbed
macrocyclic antibiotic with a narrow spectrum that
is ideal for treating infections caused by C. difficile
because it is sparing to the normal flora of the GI
tract, allowing it to be restored during therapy.
Mechanism of Action
Fidaxomicin is a ribosomal protein synthesis inhibitor
that is bactericidal. It is classified as a macrolide
by the U.S. FDA but, unlike other macrolides,
is not absorbed in the GI tract and is able to kill
susceptible organisms.
Spectrum
Good: Clostridium difficile
Poor: anything else, including Bacteroides species
and enteric GNRs
Adverse Effects
As a nonabsorbed antibiotic, fidaxomicin would be
expected to have few systemic adverse effects. Most
of the adverse effects reported in clinical trials are