Problems of Forensic Sciences 2002 Vol. 50 (L) 35-43

**WIDMARK’S EQUATION VERSUS PHARMACOKINETIC MODELLING IN BACK CALCULATION OF ALCOHOL CONCENTRATION**

**Wojciech GUBAŁA, Wojciech PIEKOSZEWSKI**

Institute of Forensic Research, Cracow

**Streszczenie**Widmark’s equation is often used for translating a measured blood alcohol concentration into a concentration of alcohol at the moment of accident, or the amount of alcohol consumed by a driver. The aim of the study was to compare the results of back calculation of alcohol concentration using Widmark’s formula and pharmacokinetic modeling. A group of forty volunteers took part in this study. The men participating in the experiment were given alcohol in the form of 40% v/v vodka, at a dose of 0.7 g/kg which was supposed to cause a maximum concentration of 1 g/l ethanol in blood, according to the theoretical calculations based on the Widmark formula. The alcohol concentration in blood samples was determined by gas chromatography. Pharmacokinetic modeling was performed using the one compartment model with first order absorption and zero order elimination, and the pharmacokinetic parameters of ethanol were also calculated using the Widmark equation. The performed research showed that the calculation of consumed dose and back calculation of alcohol concentration by pharmacokinetic modeling and the Widmark formula allowed us to draw similar conclusions. However, calculation by the Widmark equation led to an overestimation of the maximal concentration of ethanol after consumption of a certain dose of alcohol.

**Słowa kluczowe**Widmark calculations; Ethanol; Pharmacokinetic modeling.