Fidaxomicin merits placement ahead of vancomycin and other agents in treatment of Clostridium difficile infections, according to a network meta-analysis by UK researchers.

The study, Dr. Venkataraman Subramanian told Reuters Health by email, “is the most up-to-date and comprehensive synthesis of evidence for pharmacological treatments of C. difficile.”

As reported in The Lancet Infectious Diseases, Dr. Subramanian of St James University Hospital, Leeds, and colleagues included 24 trials, involving 5361 patients and 13 different treatments, in their analysis. The researchers rated the quality of evidence overall as moderate to low.

“Our results,” Dr. Subramanian continued, “indicate that fidaxomicin has the strongest evidence for providing a sustained symptomatic cure and was superior to vancomycin for all patient groups except those with severe infections with C. difficile.” The odds ratio for fidaxomicin was 0.67.

“Metronidazole, on the other hand,” he added, “cannot be recommended for treatment of C. difficile as cure rates were significantly less compared to vancomycin (OR, 0.73) and fidaxomicin (OR, 0.49) and it ranked 11th of all 13 treatment options studied.”

Also superior to metronidazole were teicoplanin (OR 0.27), ridinilazole (OR 0.41), and surotomycin (OR 0.66).

Bacitracin was inferior to teicoplanin (0.22) and fidaxomicin (0.40). Tolevamer was inferior to all drugs except for LFF571 (0.50) and bacitracin (0.67).

Dr Subramanian said teicoplanin and ridinilazole “could potentially be effective treatments, however their routine implementation should await results from larger blinded randomized controlled trials.”

The investigators conclude that fidaxomicin “has the strongest evidence for being the most effective treatment in providing a long-term cure against C. difficile. Apart from affordability, there is little evidence to support use of metronidazole as a first-line treatment against infections with C. difficile.”

Dr. Herbert L DuPont of the University of Texas Medical School and School of Public Health, Houston, co-author of an accompanying editorial, told Reuters Health by email, “The various available clinical trials provide clear evidence of the relative value of anti-C. diff drugs.”

“Metronidazole continues to be used worldwide, but is inferior to all drugs and should probably not be used except when oral drugs cannot be used—then use it IV with other treatments,” he said.

Fidaxomicin is the most effective of the available drugs, he concluded, but in the U.S., where medical costs are “in silos (pharmacy, hospital, versus physician costs), we focus on the least expensive approved drug (e.g., metronidazole and vancomycin) that probably in the long run costs our society more because of future cost of drugs and hospitalization.”