Acute poisoning with pine oil - metabolism of monoterpenes

A patient attempting suicide ingested 400-500 ml pine oil and was admitted to the clinic. Since more than the lethal dose had been ingested hemoperfusions with activated charcoal and amberlite and a hemodialysis were performed. The composition of the ingested pine oil was determined by gaschromatography/mass spectrometry. Four monoterpenes were identified: 57% alpha-pinene, 8% beta-pinene, 26% carene, 6% limonene and 3% other hydrocarbons. The blood and urine monoterpene concentrations were continuously monitored. The data suggest that monoterpenes are poorly resorbed in the gastrointestinal tract. The resorbed portion of the hydrocarbons cumulates in the lipophilic body compartments and is slowly metabolized and then excreted by the kidneys. The main metabolic pathways are hydratation, hydroxylation, rearrangement, and acetylation. Five metabolites were identified.