Isopropyl alcohol has a half-life of approximately 3 hours and a volume of distribution similar to that of ethanol. It is readily absorbed through the GI tract and is metabolized at approximately 50% of the rate of ethanol. The metabolism of isopropanol occurs mainly by alcohol dehydrogenase to produce acetone, carbon dioxide, and water. The fatal dose of ingestion is 250 mL. Both isopropyl alcohol and its major metabolite, acetone, are CNS depressants.
CNS depression is the principal symptom of acute isopropanol intoxication. In addition, it produces significant GI irritation, which may be manifested by nausea and vomiting, including hematemesis and melena, abdominal pain, and gastritis. Other symptoms include confusion, coma, hypertension, respiratory failure, and death. The diagnosis of isopropanol intoxication is difficult to make.
The diagnosis of isopropanol intoxication is difficult to make. Clues to the diagnosis include acetonuria, acetonemia and hyperosmolarity without glycosuria, hyperglycemia, or acidosis. Gas chromatography is generally considered to be the best technique to determine isopropanol blood concentrations. Treatment includes supportive care, activated charcoal with gastric lavage, and hemodialysis in severe poisoning.