Although no longer indicated as a first-line therapy, metronidazole still has therapeutic benefits and can serve patients in certain settings and circumstances.
In 2017, the Infectious Disease Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) published their updated clinical practice guidelines giving first-line therapy designation to vancomycin or fidaxomicin for all C difficile infections, thus supplanting metronidazole as the indicated therapy of choice.
Metronidazole was first discovered in the 1950s and has been indicated for a number of medical conditions and uses through the years including bacterial vaginosis, trichomoniasis, giardiasis, dracunculus, C difficile, E histolytica, preterm births, hypoxic radiosensitizer, and perioral dermatitis.
The change in the IDSA/SHEA guidelines did not mean metronidazole could not be indicated for use anymore. In fact, the guidelines said it can be used in settings where vancomycin or fidaxomicin might not be available. The drug is readily accessible internationally, and still has value in locations overseas.
Of course, cost is also a major factor in prescribing practices for metronidazole as the therapy is cost-effective.
Wiep Klaas Smits, PhD, Department of Medical Microbiology, Leiden University Medical Center, says the change is a transitional process and still see value in the metronidazole. Smits believes clinicians should follow the guidelines, but knows costs, therapy availability, and patient profiles, all play roles in make decisions in prescribing.
“We should not expect people to stop using metronidazole from one day to the other because the guidelines changed,” Smits said. “It is important to keep in mind which patient groups this drug still might be effective.”
Smits will presenting his session at 12:25pm today, Metronidazole For the Treatment of C. difficile Infections: On the Way Out? today at the 9th Annual International C. Diff Conference & Health EXPO.
His research team investigated plasmid resistance using metronidazole in longitude studies, and although not widely seen, it is something to be aware of.
“We don’t routinely test for antimicrobial susceptibility against metronidazole,” Smits said.
Contagion spoke with Smits about his presentation, circumstances where metronidazole might be indicated, and some insights regarding the new research on plasmid resistance.