As cannabis has become more accessible, use of alternative methods for cannabis administration such as vaporizers has become more prevalent. Most prior controlled pharmacokinetic evaluations have examined smoked cannabis in frequent (often daily) cannabis users. This study characterized the urinary excretion profile of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH), the primary analytical outcome for detection of cannabis use, among infrequent cannabis users following controlled administration of both smoked and vaporized cannabis. Healthy adults (N = 17), with a mean of 398 (range 30-1,825) days since last cannabis use, smoked and vaporized cannabis containing 0, 10, and 25 mg of Δ9-tetrahydrocannabinol (THC) across six outpatient sessions. Urinary concentrations of THCCOOH were measured at baseline and for 8 h after cannabis administration. Sensitivity, specificity, and agreement between three immunoassays (IA) for THCCOOH (with cutoffs of 20, 50, and 100 ng/mL) and gas chromatography-mass spectrometry (GC/MS) results (confirmatory concentration of 15 ng/mL) were assessed. THCCOOH concentrations peaked 4-6 h after cannabis administration. Median maximum concentrations (Cmax) for THCCOOH were qualitatively higher after administration of vaporized cannabis compared to equal doses of smoked cannabis. Urine THCCOOH concentrations were substantially lower in this study relative to prior examinations of experienced cannabis users. The highest agreement between IA and GC/MS was observed at the 50 ng/mL IA cutoff while sensitivity and specificity were highest at the 20 and 100 ng/mL IA cutoffs, respectively. Using federal workplace drug-testing criteria (IA cutoff of 50 ng/mL and GC/MS concentration ≥15 ng/mL) urine specimens tested positive in 47% of vaporized sessions and 21% of smoked sessions with active THC doses (N = 68). Urinary concentrations of THCCOOH are dissimilar after administration of smoked and vaporized cannabis, with qualitatively higher concentrations observed after vaporization. Infrequent users of cannabis may excrete relatively low concentrations of THCCOOH following acute inhalation of smoked or vaporized cannabis.

中文翻译：

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不常吸食大麻者吸食和汽化大麻后 11-Nor-9-Carboxy-Δ9-四氢大麻酚 (THCCOOH) 的尿排泄情况。


随着大麻变得越来越容易获得，使用蒸发器等替代大麻管理方法变得更加普遍。大多数先前的受控药代动力学评估都检查了经常（通常是每天）大麻使用者的吸食大麻。这项研究描述了 11-正-9-羧基-Δ9-四氢大麻酚 (THCCOOH) 的尿液排泄情况，这是在不经常使用大麻的人中控制吸食和汽化大麻后检测大麻使用的主要分析结果。健康成年人 (N = 17)，自上次使用大麻以来平均 398 天（范围 30-1,825）天，在六次门诊期间吸食和蒸发含有 0、10 和 25 毫克 Δ9-四氢大麻酚 (THC) 的大麻。在基线和大麻施用后 8 小时内测量 THCCOOH 的尿液浓度。 THCCOOH 的三种免疫测定 (IA)（截止值分别为 20、50 和 100 ng/mL）与气相色谱-质谱 (GC/MS) 结果（确认浓度为 15 ng/mL）之间的灵敏度、特异性和一致性评估。 THCCOOH 浓度在大麻施用后 4-6 小时达到峰值。与同等剂量的熏制大麻相比，施用汽化大麻后 THCCOOH 的中位最大浓度 (Cmax) 在质量上更高。相对于之前对有经验的大麻使用者的检查，本研究中尿液 THCCOOH 浓度显着降低。在 50 ng/mL IA 截止值处观察到 IA 和 GC/MS 之间的最高一致性，而灵敏度和特异性分别在 20 ng/mL 和 100 ng/mL IA 截止值处最高。 使用联邦工作场所药物测试标准（IA 截止值 50 ng/mL 且 GC/MS 浓度≥15 ng/mL），在使用活性 THC 剂量的汽化疗程中 47% 和吸烟疗程中 21% 的尿液样本中检测出阳性（N = 68） ）。服用熏制和汽化大麻后，尿液中 THCCOOH 的浓度有所不同，汽化后观察到的浓度更高。不经常吸食大麻的人在急性吸入烟熏或汽化大麻后可能会排出相对较低浓度的 THCCOOH。