Methanol Kinetics in Chronic Kidney Disease After Fomepizole: A Case Report

Methanol is a common toxicant in the United States, especially from automotive products. Its kinetics have been described previously and typically involve little urinary excretion. We present a case of prolonged methanol half-life in a patient with chronic kidney disease. An 80-year-old male with a baseline glomerular filtration rate of 24 mL·min·1.73 m was transferred to our facility after unintentional methanol ingestion. The original facility had treated him with an oral ethanol load; upon arrival to our facility, he was immediately loaded with fomepizole. His initial serum methanol concentration was 66.1 mg/dL. After a risk/benefit discussion, we decided not to perform hemodialysis on the patient and he was treated with fomepizole and supportive care. After 6 days as an inpatient, the patient's methanol level had declined to 22 mg/dL, fomepizole was discontinued, and the patient was able to be discharged without apparent complications. Based on the exponential best fit line for the patient's methanol concentrations, his methanol half-life during fomepizole treatment was approximately 70 hours, significantly longer than the 30-50 hours typically reported. The reasons for this difference are unclear. This report is limited by being a single case. Further study on the kinetics of methanol in the setting of chronic kidney disease is needed.