Two Fatal Intoxications Involving 3-Methoxyphencyclidine.

3- and 4-methoxyphencyclidine (3-MeO-PCP, 4-MeO-PCP), structural analogs of phencyclidine (PCP), were among the first legal PCP alternatives to show up on the novel psychoactive substances (NPS) market in Europe in the 2000s. Their structural similarities to PCP and ketamine likely contribute to their demonstrated dissociative anesthetic effects. Limited information exists in the literature about toxic and lethal concentrations of these drugs in biological samples. This case report presents the first two death cases in Washington State in which 3-MeO-PCP was identified. Alkaline drug screen analysis by gas chromatography-mass spectrometry (GC-MS) revealed a peak with a retention time similar to PCP and base peak of m/z 230. Certified reference materials for 3-and 4-MeO-PCP were obtained and the isomers were able to be distinguished based on different retention times and mass spectra. A quantitative GC-MS method was developed and validated for casework, utilizing a dynamic range of 10-1,000 ng/mL and a limit of detection of 1 ng/mL. Postmortem (peripheral/central) blood samples were analyzed using this method and the resulting concentrations were 0.63 and 3.2 mg/L of 3-MeO-PCP. Methamphetamine (0.11 mg/L) was additionally detected in the blood of one of the decedents; while the second decedent was additionally positive for ethanol (0.047 g/100 mL), bupropion (1.8 mg/L), delorazepam, paroxetine and mitragynine. The results presented in this case report are higher than previously reported concentrations in fatal cases, but the presence of polysubstance abuse is consistent with previously reported NPS intoxications. Both of these individuals were in drug rehabilitation facilities prior to their deaths; however, users continue to be drawn to 3-MeO-PCP due to its dissociative effects and its accessibility on the internet.