What is "fidaxomicin"

n. (context medicine English) A particular narrow-spectrum macrocyclic antibiotic drug

Fidaxomicin (trade names Dificid, Dificlir, and previously OPT-80 and PAR-101) is the first in a new class of narrow spectrum macrocyclic antibiotic drugs. It is a fermentation product obtained from the actinomycete Dactylosporangium aurantiacum subspecies hamdenesis. Fidaxomicin is non-systemic, meaning it is minimally absorbed into the bloodstream, it is bactericidal, and it has demonstrated selective eradication of pathogenic Clostridium difficile with minimal disruption to the multiple species of bacteria that make up the normal, healthy intestinal flora. The maintenance of normal physiological conditions in the colon can reduce the probability of Clostridium difficile infection recurrence.

It is marketed by Cubist Pharmaceuticals after acquisition of its originating company Optimer Pharmaceuticals. The target use is for treatment of Clostridium difficile infection.

Fidaxomicin is available in a 200 mg tablet that is administered every 12 hours for a recommended duration of 10 days. Total duration of therapy should be determined by the patient's clinical status. It is currently one of the most expensive antibiotics approved for use. A standard course costs upwards of £1350.