Fomepizole use is often suboptimal in cases of toxic alcohol poisoning

Study objectives: Fomepizole received US Food and Drug Administration approval in 1999 as an easier alternative to ethanol infusion for antidotal treatment of toxic alcohol poisoning. Because significant delays to adequate alcohol dehydrogenase (ADH) inhibition commonly occur when ethanol is used, we seek to determine whether fomepizole availability reduced delays to therapeutic ADH inhibition in cases of ethylene glycol and methanol ingestions. Methods: A 2-year retrospective analysis was conducted of all potential ethylene glycol and methanol ingestions reported to a regional poison center. Cases without ethylene glycol or methanol serum assays were excluded from analysis. Results: One hundred thirty-three cases were identified; 102 (77%) of 133 had complete data for analysis. Immediate ADH inhibition was recommended in 79 (77%) of 102 cases. Fomepizole was recommended in 61 (77%) of 79; ethanol was recommended as an alternative in 32 (52%) of 61 of these cases if fomepizole was not immediately available. Ethanol alone was recommended in 18 (23%) of 79 cases because fomepizole was not on hospital formulary. Fomepizole was eventually administered in 39 (64%) of 61 cases where recommended, but delays to administration occurred in 19 (49%) of 39 cases. Delays were more likely in cases in which fomepizole and ethanol were both recommended (odds ratio [OR] 7.3, 95% confidence interval [CI] 2.4 to 21.8; P P Conclusion: As are most antidotes, fomepizole is most useful if immediately available when needed. Despite its ease of administration, fomepizole is used less frequently than recommended by poison center staff and is often delayed in cases with confirmed toxicity. It is unclear why delays were more likely when a choice in ADH inhibition was given.