Fidaxomicin Flashcards
What is fidaxomicin? what is it used for?
macrocyclic antibiotic, was approved by the FDA in 2011 for the treatment of CDI
MOA of fidaxomicin
Fidaxomicin binds to ribonucleic acid (RNA) polymerase and thus inhibits RNA synthesis. Fidaxomicin is bactericidal
Is there any resistance to fidaxomicin?
Resistance to fidaxomicin is rare and is not related to resistance with other macrolides or other antibiotic classes.
What is the activity of fidaxomicin
Fidaxomicin has activity primarily against Clostridium species, particularly C. difficile.
How is fidaxomicin absorbed?
Fidaxomicin is administered orally, but minimal amounts of the drug are absorbed
How is fidaxomicin metabolized?
Fidaxomicin is metabolized in the intestine primarily through hydrolysis. It does not undergo metabolism through CYP enzymes
How is fidaxomicin excreted?
Greater than 92% of fidaxomicin is excreted in feces, and 0.59% is excreted in the urine.
Are serum levels of fidaxomicin affected by renal impairment?
Serum levels are not affected by renal impairment.
Precautions/Adverse Reactions of fidaxomicin
Use caution if a patient has a macrolide allergy.
reactions including acute dyspnea, angioedema, rash, and pruritus have been observed
What Drug Interactions might fidaxomicin have
Fidaxomicin may have synergistic effects with rifampin or rifaximin
What is the Drug Selection Rationale for fidaxomicin
Fidaxomicin treatment should only be initiated for documented or highly suspected CDI. Although fidaxomicin is highly effective, is safe, and has the least impact on GI microbes, its cost has severely limited its use
