TABLE 1

Major enzymes involved in the metabolism of opioids and/or other drugs detected in postmortem blood samples obtained from kratom-related death cases in Colorado (Gershman et al., 2019)

Case no.Blood Mitragynine Concentration (μM)Other DrugsMajor Enzyme(s)References
1PositiveaButyryl-fentanyl, oxycodone, etizolam, diphenhydramine, THCCYP3A, CYP2D6Lalovic et al. (2004); Niwa et al. (2005); Kanamori et al. (2019)
2PositiveOxycodone, fluoxetine, pseudoephedrineCYP3A, CYP2D6Lalovic et al. (2004); LLerena et al. (2004)
30.04Etizolam, 5-MeO-AMTCYP3ANiwa et al. (2005)
4PositiveMorphine, codeineUGT2B7, CYP3A, CYP2D6Crews et al. (2014)
50.35Oxycodone, tramadol, topiramate, diphenhydramine, zolpidemCYP3A, CYP2D6Pichard et al. (1995); Miotto et al. (2017); Yamamoto et al. (2017)
65.3CitalopramCYP3A, CYP2C19, CYP2D6von Moltke et al. (2001)
73.5Furanyl-fentanylNANA
82.5Temazepam, olanzapine, sertraline, clonazepamCYP3A, CYP2C9, CYP2C19, CYP2D6, UGT2B7Kobayashi et al. (1999); Urichuk et al. (2008); Tóth et al. (2016)
90.423,4-Dimethoxy-N-methylamphetamineNANA
106.7Etizolam, nordiazepam, mirtazapineCYP3A, CYP2D6, CYP1A2Ono et al. (1996); Störmer et al. (2000); Niwa et al. (2005)
11122,4,5-TrimethoxyamphetamineCYP2D6Ewald and Maurer (2008)
120.62OxycodoneCYP3A, CYP2D6Lalovic et al. (2004)
131.9Oxycodone, fentanyl, cocaineCYP3A, CYP2D6, esterasesKamendulis et al. (1996); Guitton et al. (1997); Kanamori et al. (2019)
14Positive—b——
15PositiveU-47700NANA

  • 5-MeO-AMT, 5-methoxy-α-methyltryptamine; NA, information not available; THC, tetrahydrocannabinol; U-47700, synthetic opioid; UGT, uridine diphosphate-glucuronyltransferase.

  • ↵a Qualitative detection.

  • ↵b No other drugs reported.