C difficile cases present many challenges to pharmacists

December 8, 2008

When dealing with Clostridium difficile infections in the healthcare setting, "if we don't do the right thing, patients die," said Rob Owens, PharmD, co-director of the Antimicrobial Stewardship Program at Maine Medical Center and assistant clinical professor at the University of Vermont, College of Medicine, at a talk on the diagnosis and treatment of C difficile.

When dealing with Clostridium difficile infections in the healthcare setting, "if we don't do the right thing, patients die," said Rob Owens, PharmD, co-director of the Antimicrobial Stewardship Program at Maine Medical Center and assistant clinical professor at the University of Vermont, College of Medicine, at a talk on the diagnosis and treatment of C difficile.

Dr. Owens discussed the increasing prevalence of C difficile, the rates of which tripled between 2000 and 2005. The prevalence of the infection is increasing not just in hospitals and long-term care facilities, but also in the community.

Diagnosis of this infection is a challenge, said Dr. Owens, stating that "thought is all over the map on how to diagnose C difficile right now." Current tests, including enzyme immunoassay, tissue culture cytotoxicity, organism identification, and stool culture, each have various limitations such as sensitivity issues, labor intensity, nonspecificity, and the potential for false positives.

Because C difficile strains are highly sporulated, there is "no such thing as prophylaxis for C difficile" as available drugs have no activity against spores, said Dr. Owens. These spores can also survive in the environment for long periods of time, similar to anthrax.

Disease recurrence is often a problem in patients with C difficile infection; this recurrence is more likely to occur in patients who are unable to mount an adequate immune response. Patients who are able to mount an adequate response are 48 times less likely to develop recurrent disease.

Discussing management of C difficile infections in hospitals and long-term care facilities, Dr. Owens asked, "Who is to blame? Everyone. Everyone who comes into a patient's room." Studies have demonstrated that hospital personnel, including physicians, nurses, and housekeepers, are very likely to have hand cultures positive for C difficile after contact with a culture-positive patient.

Dr. Owens said that current evidence shows that metronidazole is just as effective as vancomycin in treating mild-to-moderate cases of C difficile. For severe infections, vancomycin is the drug of choice. He pointed out, however, that treatment duration needs to be limited, saying, "The longer you're on the treatment, the more likely you are to get recurrence." He added that, according to the current evidence, probiotics and cholestyramine have no beneficial effect on C difficile infections.

"We're constantly students of C difficile," Dr Owens concluded. "What I'm telling you now probably has a half-life of one month."