Double Suicide Due to the Ingestion of Levamisole-Adulterated Cocaine: Case Report and Review of the Literature

Abstract

Suicide is a major public health issue and the risk of attempting and committing suicide increases with age. We present the case of an elderly couple who decided to commit suicide together by self-poisoning using levamisole-adulterated cocaine. The choice of committing a double suicide, the method selected (self-poisoning), the drug self-administered (cocaine), and the route of administration (ingestion) are events rarely encountered in the forensic pathology practice, especially not in combination. In this article, we will review the literature regarding the frequency and features of these methods of suicide. An overview of the effects and mechanism of action of levamisole is also provided, highlighting the importance of including this substance and its metabolites in the routine toxicological analyses for cocaine deaths.

Analysis of tetramisole metabolites – Is “Aminorex” found in forensic samples of cocaine users actually 4‐phenyl‐2‐imidazolidinone?

“…On the one hand, there are two experiments in which aminorex was detected in serum 29 or urine 9,17 after controlled oral levamisole ingestion. On the other hand, there are studies examining the presence of aminorex in samples of cocaine users including two case reports of fatal cocaine intoxications 20,25 as well as four studies examining forensic urine or serum sample collectives. 10,17,21,29 In the following comparison of studies examining forensic sample collectives (Table 3), it should be considered as a limiting factor that no information on the cocaine consumed (purity, adulterants) is available.…”

“…10,17,21,29 In the following comparison of studies examining forensic sample collectives (Table 3), it should be considered as a limiting factor that no information on the cocaine consumed (purity, adulterants) is available. While some of these studies only report qualitative data anyway, 17,20 the few aminorex detections in quantitative studies are mostly below the LOQ. The highest reported aminorex concentration is 45 ng/ml in urine (controlled intake of 100 mg levamisole 9 ) or 8.92 ng/ml in blood (post-mortem sample 25 ).…”

“…Putatively, aminorex had been qualitatively detected in post-mortem urine but not in blood. 20 Another explanation for the frequent detection of aminorex in studies after controlled oral intake 9,17,29 compared to samples from cocaine users is the significantly higher administered dose. Also in horses, the dose given that resulted in a detectable amount of aminorex was much higher.…”

“…15 Soon afterwards, aminorex was found in human urine after controlled oral intake of levamisole. 17 From then on, it is often cited as a human metabolite of PTHIT [18][19][20] even though data relating to the analytical proof of aminorex in forensic samples is still quite rare and contradictory in the literature. 10,21 Moreover, there are further less known putative metabolites of PTHIT sharing the same sum formula (C 9 H 10 N 2 O).…”

“…The resulting TIC-chromatograms are shown in Figure5a,b. Since aminorex has been analysed before as 2TMS-derivative17,20,25 exhibiting a base peak at m/z 291, extracted ion chromatograms were generated for this mass. By doing so, it can be recognised that both substances co-elute at a retention time of 8.6 min.…”