[Has the transdermal patch gone up in smoke? A fatal fentanyl intoxication].

Recently, there has been an increase in fentanyl-related overdoses following administration of transdermal patches by the buccal, oral or intravenous route or via inhalation. A fatal intoxication is reported with clear evidence from toxicological analysis. However, the administration route and the fate of the patch remained elusive at the end of the investigations. Alcohol was present in the blood in small quantity (0.024%), whereas no other drug could be detected by basic strategies. Autopsy and microscopic examination failed to find sufficient evidence for a diagnosis. Fentanyl and norfentanyl were determined from body fluids and tissues by LC/MS/MS following liquid/liquid extraction. Both analytes were detectable in all specimens under investigation except muscle tissue where norfentanyl was absent. While the fentanyl concentration in the blood was considered potentially life-threatening on the basis of data obtained from living persons and fentanyl-related deaths, it was difficult to assess the other values because no comparative data were available. The history and circumstances of the case together with the toxicological findings suggest an intravenous or inhalative application of the patch. The latter assumption is supported by the fact that the body was found holding a cigarillo butt in his right hand. The case underlines the necessity to study fentanyl-related deaths more closely to allow a better interpretation of potential intoxications.