Can oral fluid cannabinoid testing monitor medication compliance andor cannabis smoking during oral THC and oromucosal Sativex administration
We characterize cannabinoid disposition in oral fluid (OF) after dronabinol, synthetic oral Δ(9)-tetrahydrocannabinol (THC), and Sativex, a cannabis-extract oromucosal spray, and evaluate whether smoked cannabis relapse or Sativex compliance can be identified with OF cannabinoid monitoring. 5 and 15 mg synthetic oral THC, low (5.4 mg THC, 5.0 mg cannabidiol (CBD)) and high (16.2 mg THC, 15.0 mg CBD) dose Sativex, and placebo were administered in random order (n14). Oral fluid specimens were collected for 10.5 h after dosing and analyzed for THC, CBD, cannabinol (CBN), and 11-nor-9-carboxy-THC (THCCOOH). After oral THC, OF THC concentrations decreased over time from baseline, reflecting residual THC excretion from previously self-administered smoked cannabis. CBD and CBN also were rarely detected. After Sativex, THC, CBD and CBN increased greatly, peaking at 0.25-1 h. Median CBDTHC and CBNTHC ratios were 0.82-1.34 and 0.04-0.06, respectively, reflecting cannabinoids composition in Sativex. THCCOOHTHC ratios within 4.5 h post Sativex were ≤ 1.6 pgng, always lower than after oral THC and placebo. THCCOOHTHC ratios increased throughout each dosing session. Lack of measurable THC, CBD and CBN in OF following oral THC, and high OF CBDTHC ratios after Sativex distinguish oral and sublingual drug delivery routes from cannabis smoking. Low THCCOOHTHC ratios suggest recent Sativex and smoked cannabis exposure. These data indicate that OF cannabinoid monitoring can document compliance with Sativex pharmacotherapy, and identify relapse to smoked cannabis during oral THC medication but not Sativex treatment, unless samples were collected shortly after smoking.