Case Presentation: Teriflunomide is a pyrimidine synthesis inhibitor used in management of Relapsing Remitting Multiple Sclerosis (RRMS). Leflunomide is the active agent which has been used in rheumatoid arthritis. Chronic diarrhea has been associated with both of these. However, there is no evidence in literature to suggest clostridium difficile (C.Diff) diarrhea associated with these agents. We present a unique case of C.Diff colitis in a patient on this immunosuppressive agent.A 47-year-old female with a history of RRMS on Teriflunomide and Dalfampridine presented to the emergency department with complaints of nausea, vomiting, diarrhea and abdominal pain. She also had reactivation of prior neurological deficits that was considered to be pseudo-exacerbation of MS. There was no history suggestive of recent use of antibiotics or change in her home medications. The patient then developed signs of severe sepsis with worsening diarrhea and was admitted to the intensive care unit for severe C.Diff infection. Teriflunomide was considered as a causative agent and was withheld after consultation with neurology. Dalfampridine was also discontinued. Patient received appropriate antibiotics with complete resolution of her infection.
Discussion: Teriflunomide and leflunomide are associated with diarrhea. Severe infections are also reported due to immunosuppression. However, C.Diff infection has not been previously reported. In the post-marketing survey of use of teriflunomide, only two cases reported C.Diff colitis which led to drug discontinuation and changes in management of RRMS. In both these cases, patients were also taking dalfampridine. The timing of C.Diff infection in both cases was within 6 months of initiating Teriflunomide. Currently there are no guidelines on management of C.Diff infections in such cases however teriflunomide has a long half-life ( > 20 days) and requires drug elimination procedures such as use of cholestyramine / activated charcoal to hasten the elimination. Unfortunately, this was not performed in our patient and that was the likely cause of C. Diff relapse she developed after 2 weeks of discontinuation of the medication.
Conclusions: We report a case of a patient who presented with severe C.Diff colitis that was attributed to the use of teriflunomide. Since guidelines were not available, drug elimination procedures were not performed. However, this should likely be considered to reduce chance of infection relapse or antibiotic resistance. Further studies and extrapolation of data from use of other immunosuppressive agent should be considered in treating such complex cases.