The effect of ibuprofen on ethanol concentration and elimination rate.

Pursuant to a recent driving under the influence (DUI) case, a medical study of six subjects was cited reporting that ibuprofen causes a decrease in the maximum rate of elimination of ethanol. Such a drug interaction is of significant forensic science interest and warrants further examination. This study investigates the effect of ibuprofen on ethanol elimination rate and ethanol concentration in nineteen volunteers. Volunteer subjects were randomly assigned to two groups administered either a placebo followed by ethanol or ibuprofen followed by ethanol. Subjects served as their own control. Blood ethanol concentrations were monitored every 30 to 60 min for up to 4 h with Intoximeter 3000 instruments. A blood sample was drawn at the final Intoximeter test and analyzed for ethanol and ibuprofen by gas chromatography and mass spectrometry, respectively. The mean elimination rate (+/- SD) as calculated using Widmark's elimination factor was 0.018 +/- 0.006 g/dL for ethanol and 0.017 +/- 0.007 g/dL/h for ethanol with ibuprofen. Mean ethanol concentrations (g/dL +/- SD) were: 0.095 +/- 0.026 (ethanol) and 0.095 +/- 0.033 (ethanol and ibuprofen) at 30 min; 0.077 +/- 0.026 (ethanol) and 0.075 +/- 0.031 (ethanol and ibuprofen) at 150 min; and 0.089 +/- 0.025 (ethanol) and 0.087 +/- 0.030 (ethanol and ibuprofen) overall. There was no statistically significant affect of ibuprofen on either the peak blood ethanol concentration or the ethanol elimination rate (p less than or equal to 0.001). These results reveal no evidence of a significant ethanol-ibuprofen interaction.