578 - Use of Nitazoxanide, an Anti-Parasitic Drug, for Management of Norovirus Ileo-Colitis in an Allogeneic Stem Cell Transplant Patient

Abstract

Patients undergoing allogeneic stem cell transplant are at significant risk of infections due to the immunosuppression resulting from leukopenia as well as immunosuppressive agents for graft versus host disease prophylaxis or management. Organisms that normally do not result in significant clinical manifestations can cause potentially lethal outcomes in infected allogeneic stem cell transplant patients. Diarrhea resulting from infectious etiology continues to remain a significant complication associated with allogeneic stem cell transplant. Norovirus gastroenteritis is a well described phenomenon in both pediatric as well as adult allogeneic hematopoietic stem cell transplant recipients. There is no definite treatment available for managing this complication and supportive care and withdrawal of immunosuppression continues to remain the mainstay. We report the case of a 68-year-old Caucasian female who underwent a haplo-identical stem cell transplant for high-risk acute myeloid leukemia with FLT3 mutation. The patient developed diarrhea on day+4 and her stool tested positive for Clostridium difficile. Even though she initially responded to appropriate treatment for Clostridium difficile, her diarrhea recurred. Repeat testing for infectious etiology revealed the presence of norovirus while Clostridium difficile was no longer detected. The patient was treated with oral nitazoxanide 500 mg BID for 10 days with significant clinical improvement in her stool volume and frequency as well as consistency. However, she continued to shed the virus even after clinical improvement. Nitazoxanide was developed in 1970 and was initially perceived to be an anti-protozoal agent. An increasing amount of pre-clinical and clinical research has indicated that it is active against a broad variety of organisms including anaerobic gram-positive and gram-negative bacteria, mycobacterium tuberculosis, respiratory viruses as well as rotavirus and norovirus. While there is literature supporting the use of nitazoxanide in other immunosuppressed patients such as HIV infected and solid organ transplant patients, information regarding the safety and efficacy of nitazoxanide for treating norovirus in adult allogeneic stem cell transplant patients is very limited (one case report identified in Pubmed). Our case demonstrates that even in early post-transplant setting, nitazoxanide effectively controlled norovirus gastroenteritis without compromising graft function. The utility of Nitazoxanide in viral gastroenteritis in allogeneic hematopoietic transplant patients should be explored further in prospective trials.Tabled 1Pubmed search using the terms “Nitazoxanide” AND one of the following# of Items in search resultsRelevant to clinical use of Nitazoxanide for Norovirus in Hematopoietic Stem Cell transplantHematopoietic transplant31Stem cell transplant51Norovirus101 Open table in a new tab