Background: The U.S. manufacturer of fomepizole recommends dosing at 4 hour intervals when used during hemodialysis for treatment of toxic alcohol poisoning. There have been European case reports of successful use of continuous infusion (1 . 1.5 mg/kg/hr) of fomepizole during hemodialysis for toxic alcohol poisoning. Based on review of the literature and practice guidelines, this is not a common dosing regimen in the United States and few reports exist on cost comparison of continuous versus intermittent fomepizole dosing. As fomepizole is an expensive medication, cost may be a factor in dosing recommendations. We present a cost analysis of a case where continuous fomepizole was used. Case report: A 45-year-old man presented intoxicated after drinking glisterine and vodka. His blood alcohol content via breathalyzer was 0.115 g/dL and laboratory evaluation was significant for an anion gap metabolic acidosis, pH 7.34, creatinine 0.8 mg/dL, methanol concentration 58 mg/dL and isopropanol concentration 42 mg/dL. Fomepizole was given as a 15 mg/kg loading dose. The patient underwent a 6-hour-run of hemodialysis during which fomepizole was administered as a continuous infusion at 1.5 mg/kg/hr. A methanol concentration 4 hours into dialysis was 0, bicarbonate 30 mmol/L, and no anion gap was present. Fomepizole infusion was not discontinued until follow-up methanol concentration 9 hours post-dialysis (also 0). Discussion: Continuous fomepizole infusion during hemodialysis is not a typical dosing regimen recommended by poison centers. The dose used in this patient resulted in less total fomepizole during dialysis (693 mg, $ 256.41) than the typical dosing regimen of 10 mg/kg every 4 hours during dialysis (based on time of loading dose, this patient would have received a 770 mg dose 4 hours into dialysis and 385mg at end of dialysis, total $ 427). Though the infusion was scheduled to be administered only during dialysis, due to a systems error it was continued for several hours post-dialysis while awaiting a repeat methanol level. This resulted in a larger dose of fomepizole administered than originally indicated, adding an additional 1039 mg with an extra cost of $ 385. Conclusion: We present a case of successful fomepizole infusion during hemodialysis which potentially could have resulted in a reduction of total fomepizole dose and cost. The optimal rate during dialysis and length of time to continue infusion following dialysis has not been clearly delineated, and this may lead to additional and unneccesary fomepizole administration, making it difficult to determine the cost benefit of continuous infusion. Further studies are required before continuous infusion of fomepizole can be routinely recommended.