Quick answerStart
fomepizole on suspicion.
Why this is correctFomepizole blocks alcohol dehydrogenase and limits formation of toxic metabolites. The label supports immediate treatment based on history, gaps, acidosis, visual findings, crystals, or a documented concentration.
Easy analogy or mental pictureClose the metabolic factory before it converts antifreeze into kidney-damaging acids.
Memory hookOsmolar gap plus acidosis and crystals: fomepizole now.NCLEX decision ruleDo not wait for confirmatory injury when the toxic pattern supports time-sensitive antidote therapy.
Why the other choices are wrongCalcium alone and acetylcysteine do not block toxic-alcohol metabolism, and waiting permits more metabolite formation.
References
1DailyMed: Fomepizole InjectionImmediate treatment for suspected ethylene glycol or methanol poisoning and dialysis coordination