Massive Overdose of Oral Vancomycin for C. Difficle Infection In A Patient On Hemodialysis: A Case Report
R. Lee Stanley, MD; Courtney Petersen, BS; William Richardson, MD
Clostridium difficile infections [CDI] are a significant cause of morbidity in hospitalized patients and those with chronic illnesses. First-line treatment for initial and first recurrence of CDI is oral vancomycin [OV]. OV is known to have poor GI absorption, making it an excellent choice when treating CDI. There have been, however, studies and numerous case reports demonstrating risk factors for significant absorption of oral vancomycin from the GI tract, such as patients with renal insufficiency, significant inflammation of the GI tract, and taking large doses. This case is of a 56-year-old female with a past medical history of ESRD [end-stage renal disease] on hemodialysis, hypertension, HIV, and recurrent CDI, who presented to the emergency department after taking 3.75g of OV twice on back to back days. She was prescribed 150mg of OV twice a day but was confused about the instructions for her new formulary of OV. Besides an episode of loose stools, the patient denied any other symptoms. Laboratory workup revealed unremarkable electrolytes, and renal function was consistent with the patient’s baseline ESRD. Serum vancomycin levels were undetectable. The patient was educated on the proper preparation and administration of the new formulary of vancomycin. This case demonstrates the lack of systemic absorption of an extremely large dose of OV in a patient with multiple risk factors which have been documented in numerous other studies and case reports as being associated with systemic absorption of OV. To our knowledge, this is the largest unintentional amount of OV taken by a patient that demonstrated no systemic absorption and no clinical signs of toxicity. This case also highlights the importance of communication with patients, providers, pharmacists, and other allied health professionals when medication formularies are being changed.
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Keywords: Clostridium difficile infection, vancomycin overdose, systemic absorption of vancomycin, vancomycin and renal disease