The clinical significance of variations in ethanol toxicokinetics.

INTRODUCTION: Many variables affect the interpretation of an isolated ethanol level in an acutely intoxicated patient. This review demonstrates the significant variability in metabolism and elimination of ethanol, how it can differ between individuals, and the clinical importance of these variables. DISCUSSION: Isolated ethanol values in a clinical scenario are only a snapshot of a dynamic process. The individual pharmacokinetic differences of people make it extremely difficult to estimate ethanol elimination rates or calculate previous ethanol concentrations at the time of an accident because of medical-legal reasons. Not only are the techniques used in measuring ethanol concentrations in bodily fluids (blood, serum, breath, and urine) not equivalent, but also the units used to report ethanol concentrations are often misinterpreted. Acute and chronic tolerance and social adaptive changes make interpreting this isolated ethanol level extremely difficult. The purpose of this review is to enable the clinician to appropriately interpret ethanol concentrations.
CONCLUSION: The clinical evaluation of a patient's inebriation is always more reliable than an isolated ethanol level for determining disposition. Only an estimation of a current serum ethanol level can be made if the blood draw was performed hours earlier. This review is clinically important because it shows the clinically significant variability in metabolism and elimination of ethanol and how it can differ between individuals. It will also describe different ways to measure ethanol concentrations and how to compare them. Finally, the interpretation of isolated ethanol levels will be discussed.