# A client with suspected antifreeze ingestion has an anion-gap metabolic acidosis, an increased osmolar gap, and calcium oxalate crystals in the urine. Which action is the priority?

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> subject: Adverse Effects/Contraindications/Interactions  
> category: PPT

## Question

A client with suspected antifreeze ingestion has an anion-gap metabolic acidosis, an increased osmolar gap, and calcium oxalate crystals in the urine. Which action is the priority?

## Option

1. Delay poison-center consultation until renal failure confirms significant poisoning.
2. Administer oral calcium to bind ethylene glycol and correct the metabolic acidosis.
3. Administer acetylcysteine because it prevents toxic-alcohol metabolite formation.
4. Start prescribed fomepizole now and prepare for hemodialysis assessment. **✔ Correct answer**

**Correct answer: 4**

## Explanation

The findings support ethylene glycol poisoning. Fomepizole should begin on suspicion while the need for hemodialysis and correction of metabolic complications is assessed.

## In-depth explanation

Quick answer
Start fomepizole on suspicion.

Why this is correct
Fomepizole 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 picture
Close the metabolic factory before it converts antifreeze into kidney-damaging acids.

Memory hook
Osmolar gap plus acidosis and crystals: fomepizole now.

NCLEX decision rule
Do not wait for confirmatory injury when the toxic pattern supports time-sensitive antidote therapy.

Why the other choices are wrong
Calcium 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

## Clinical scenario

Toxic alcohol response
Start prescribed fomepizole, correct physiologic derangements, contact toxicology, and assess dialysis criteria.

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