. 2020 Oct;48(10):1008–1017. doi: 10.1124/dmd.120.000073

TABLE 1.

Oral and inhalational doses and estimated maximum plasma concentrations of CBD, THC, and THC metabolites used for predicting the magnitude of pharmacokinetic cannabinoid-drug interactions

Cannabinoid	CBD or THC Dose (mg)	Route of Administration	[I]_max,u (nM)^a	[I]_inlet,max,u (µM)^b
CBD	70	Oral	2.94	0.12
	700	Oral	29.4	1.24
	2000	Oral	84.0	3.55
THC	20	Oral	0.33	0.01
	130	Oral	2.15	0.03
	160	Oral	2.64	0.04
	25	Inhalation	2.72	NA
	70	Inhalation	7.62	NA
	100	Inhalation	10.89	NA
11-OH-THC	20	Oral	0.26	–
	130	Oral	1.72	–
	160	Oral	2.11	–
	25	Inhalation	0.20	NA
	70	Inhalation	0.55	NA
	100	Inhalation	0.78	NA
COOH-THC	20	Oral	3.19	–
	130	Oral	20.75	–
	160	Oral	25.54	–
	25	Inhalation	1.12	NA
	70	Inhalation	3.13	NA
	100	Inhalation	4.48	NA

NA, not applicable; –, not estimated as data on fraction of dose metabolized to these metabolites by the intestine vs. liver are not available.

^{^a}

f_u,p (CBD) = 0.07 (Taylor et al., 2019), f_u,p (THC) = 0.011 (Patilea-Vrana and Unadkat, 2019), f_u,p (11-OH-THC) = 0.012 (Patilea-Vrana and Unadkat, 2019); f_u,p (COOH-THC) was not available and assumed to be the same as of 11-OH-THC, and C_max/dose of CBD and THC after oral administration or inhalation were taken from Cox et al. (2019).

^{^b}

F_a (CBD and THC) = 1 (estimated based on FDA guidance), k_a (CBD) = 0.0048 min⁻¹ (estimated from Epidiolex (CBD) pharmacokinetic data using Phoenix WinNonlin (Phoenix WinNonlin 8.1; Certara USA, Princeton, NJ), k_a (THC) = 0.0045 min⁻¹ (Wolowich et al., 2019), Q_H (hepatic blood flow) = 1500 ml/min, and R_B (THC) (blood to plasma ratio) = 0.4 (Schwilke et al., 2009); R_B (CBD) value is not available and was assumed to be same as that for THC.