Distribution pattern of morphine and codeine in brain after heroin overdose

After intravenous administration, heroin quickly crosses the Blood-Brain Barrier to produce a rapid onset of action. However, its more protracted effects are due to the accumulation of its main metabolites, especially morphine, since heroin has an extremely short half-life [1]. Street heroin may also contain acetylcodeine, which is hydrolyzed to codeine, an active metabolite. In this study, we investigated brain distribution pattern of morphine and codeine, the main metabolites of street heroin, in fatalities due to “acute narcotism”. Brain is a very complex matrix to analyze because of its content in lipids and interfering components [2]. Therefore, it was necessary to develop a suitable sample pretreatment prior to Solid-Phase-Extraction to achieve a good recovery of the analytes. After derivatization with MSTFA, samples were analyzed by GC/MS. Specificity, accuracy, precision and linearity of the method were evaluated; the LOD and the LOQ were respectively 10ngtot/25ngtot for morphine and 5ngtot/10ngtot for codeine. Our results showed that, in heroin fatalities, morphine and codeine have a homogeneous distribution in different brain areas, such as hippocampus, frontal lobe, occipital lobe, nuclei, bulb and pons.