Increased prevalence of cannabis consumption and impaired driving are a growing public safety concern. Some states adopted per se driving laws, making it illegal to drive with more than a specified blood concentration of ∆9-tetrahydrocannabinol (THC) in a biological fluid (typically blood). Blood THC concentrations decrease significantly (∼90%) with delays in specimen collection, suggesting the use of alternative matrices, such as oral fluid (OF). We characterized 10 cannabinoids’ concentrations, including THC metabolites, in blood and OF from 191 frequent and occasional users by liquid chromatography with tandem mass spectrometry for up to 6 h after ad libitum smoking. Subjects self-titrated when smoking placebo, 5.9 or 13.4% THC cannabis. Higher maximum blood THC concentrations (Cmax) were observed in individuals who received the 5.9% THC versus the 13.4% THC plant material. In blood, the Cmax of multiple analytes, including THC and its metabolites, were increased in frequent compared to occasional users, whereas there were no significant differences in OF Cmax. Blood THC remained detectable (≥5 ng/mL) at the final sample collection for 14% of individuals who smoked either the 5.9 or 13.4% THC cigarette, whereas 54% had detectable THC in OF when applying the same cutoff. Occasional and frequent cannabis users’ profiles were compared, THC was detectable for significantly longer duration in blood and OF from frequent users. Detection rates between frequent and occasional users at multiple per se cutoffs showed larger differences in blood versus OF. Understanding cannabinoid profiles of frequent and occasional users and the subsequent impact on detectability with current drug per se driving limits is important to support forensic interpretations and the development of scientifically supported driving under the influence of cannabis laws.

中文翻译：

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经常和偶尔吸食大麻的人的血液和口腔液中的大麻素特征

大麻消费的流行和驾驶受损是一个日益严重的公共安全问题。一些州通过了本身的驾驶法，规定在生物体液（通常是血液）中使用超过规定的 ∆9-四氢大麻酚 (THC) 血液浓度驾驶是违法的。随着标本采集延迟，血液 THC 浓度显着降低（~90%），表明使用替代基质，例如口腔液（OF）。我们在随意吸烟后长达 6 小时，通过液相色谱和串联质谱法对 191 名经常和偶尔使用的使用者的血液和 OF 中 10 种大麻素的浓度进行了表征，包括 THC 代谢物。受试者在吸食安慰剂、5.9 或 13.4% THC 大麻时自行滴定。在接受 5 的个体中观察到更高的最大血液 THC 浓度 (Cmax)。9% THC 与 13.4% THC 植物材料。在血液中，与偶尔使用者相比，包括 THC 及其代谢物在内的多种分析物的 Cmax 频繁增加，而 OF Cmax 没有显着差异。对于 14% 吸食 5.9% 或 13.4% THC 香烟的个体，血液 THC 在最终样本收集时仍可检测到（≥5 ng/mL），而在应用相同临界值时，54% 在 OF 中可检测到 THC。比较了偶尔和频繁使用大麻使用者的资料，在血液和频繁使用者的 OF 中可检测到 THC 的持续时间明显更长。频繁和偶尔用户之间在多个本身截止值的检测率显示血液与 OF 的差异更大。