Identification of anabolic steroids in serum, urine, sweat and hair - Comparison of metabolic patterns

Anabolic steroids usually undergo a complex metabolism which is mainly dependent on structural variation and application pathway. In contrast to doping analysis, where the presence of a prohibited substance constitutes a doping offence without regarding the origin or application, in forensic cases any information related to anabolic steroids may be required to evaluate the cause of death, liability of defendants, or self-consumption. 19-Norsteroids proved to be appropriate model compounds for the investigation, because of their prevalence in recent doping cases, analytical and biochemical similarity to endogenous steroids, well explored biochemistry, and the availability of numerous reference standards. Typical urinary metabolites are conjugates of terminal biotransformation products like norandrosterone-glucuronide, which are relatively unspecific and do not reveal details about administration time, pathway, dosages or structural details. Therefore, metabolic patterns in blood, hair and sweat were examined to study metabolism, distribution and incorporation behaviour of the steroids and hence the traceability in the respective matrices. Concentration profiles of the steroids in blood and the resulting bioavailability show distinct particularities after oral or transdermal application of steroids. Oral application of steroid precursors is followed by extensive first pass biotransformation of the steroid to inactive metabolites, while transdermal administration appears to be an efficient pathway, leading to effective and durable concentrations of active steroids in blood. Due to the mutual similarity of metabolic patterns in hair and sweat corresponding to the regional presence of sweat and sebum glands, steroid incorporation appears to proceed mainly via sweat absorption. (C) 2003 Elsevier Science B.V All rights reserved.