Influence of Paracetamol and Acetylsalicylic Acid on the Toxicokinetics of Toluene

To study the influence of paracetamol and acetylsalicylic acid on the toxicokinetics of toluene, 2 groups of 10 male volunteers were exposed to toluene vapor (3.25 mmol/m3, 4 hr) at two different exposure occasions: toluene alone and toluene + analgesics. Solvent concentrations in blood and hippuric acid concentrations in urine were measured during the exposure period and 3 hr after exposure. The concentration of toluene in blood increased after ingestion of paracetamol or acetylsalicylic acid, as compared to the control exposure. The ingestion of paracetamol significantly increased the area under the blood concentration versus time curve (P less than 0.05) and the apparent blood clearance was significantly reduced (P less than 0.05) after ingestion of paracetamol but not after ingestion of acetylsalicylic acid. No statistically significant differences in the urinary excretion of hippuric acid were found.