Chemical Analysis of Massive Crystalluria Following Primidone Overdose

Abstract

A 43-year-old woman was hospitalized with a 36-hr. history of stupor and massive crystalluria following an apparent suicide attempt. Toxicologic studies revealed phenobarbital and primidone in both blood and urine. Col-lection, purification, and chemical analysis of the urinary crystals are described. Microscopic examination, melting-point studies, infrared and ultra-violet spectroscopy, and thin-layer and gas–liquid chromatography identified the crystals as primidone. The clinical utility of crystalluria in the diagnosis of primidone overdosage is emphasized.