Cannabinoids and drug metabolizing enzymes: potential for drug-drug interactions and implications for drug safety and efficacy

Figures & data

Figure 1. The major metabolic pathway of THC. Abbreviations: CYP: cytochrome P450; UGT: UDP-glucuronosyltransferase.

Figure 2. CBD biotransformation pathway by CYP and UGT enzymes. The CYP enzymes responsible for the metabolism of 7-OH-CBD are unknown. Abbreviations: CYP: cytochrome P450; UGT: UDP-glucuronosyltransferase.

Table 1. Reversible inhibition of recombinant CYPs and HLM by THC.

Microsomal Protein*	Probe Substrate	IC50**	Ki**	IC50,u**^,╪	Ki,u**^,╪	References
rCYP1A1	7-Ethoxyresorufin	-	4.8	-	-	Yamaori et al., 2010 [146]
rCYP1B1	7-Ethoxyresorufin	-	2.5	-	-	Yamaori et al., 2010 [146]
rCYP1A2	7-Ethoxyresorufin	-	7.5	-	-	Yamaori et al., 2010 [146]
	Phenacetin	-	-	0.12	0.090	Nasrin et al., 2021a [74]
rCYP2A6	Coumarin	-	29	-	-	Yamaori et al., 2011c [152]
rCYP2B6	7-Benzoxyresorufin	-	2.8	-	-	Yamaori et al., 2011c [152]
	Bupropion	-	-	0.43	0.25	Nasrin et al., 2021a [74]
rCYP2C9	(S)-Warfarin	2.8	1.4	-	-	Yamaori et al., 2012 [151]
	Diclofenac	1.0^1	1.4^1	0.19^2	0.073^2	Yamaori et al., 2012^1 [151]; Nasrin et al., 2021a^2 [74]
rCYP2C19	(S)-Mephenytoin	4.4	1.9	-	-	Jiang et al., 2013 [102]
	Omeprazole	2.2^1	-	0.15^2	0.056^2	Jiang et al., 2013^1 [102]; Nasrin et al., 2021a^2 [74]
rCYP2D6	Dextromethorphan	17^1	-	0.47^2	0.11^2	Yamaori et al., 2011a^1 [149]; Nasrin et al., 2021a^2 [74]
	AMMC^#	21	-	-	-	Yamaori et al., 2011a [149]
rCYP3A4	Diltiazem	-	>50	-	-	Yamaori et al., 2011b [150]
rCYP3A5	Diltiazem	-	36	-	-	Yamaori et al., 2011b [150]
rCYP3A7	Diltiazem	-	30	-	-	Yamaori et al., 2011b [150]
HLM	7-Ethoxyresorufin	-	4.7	-	-	Yamaori et al., 2011b [150]
	Phenacetin	-	-	0.060^1, 0.028^2, 0.27^3	0.10^3	Bansal et al., 2020^1 [147]; Bansal et al., 2022^2 [148]; Nasrin et al., 2021a^3 [74]
	Bupropion	-	-	0.40^1, 0.97^2	0.38^2	Bansal et al., 2022^1 [147]; Nasrin et al., 2011a^2 [74]
	Amodiaquine	-	-	0.67	-	Bansal et al., 2022 [148]
	(S)-Warfarin	2.3	1.5	-	-	Yamaori et al., 2012 [151]
	Diclofenac	4.4^1	1.3^1	0.012^2, 0.0050^3, 0.37^4	0.17^4	Yamaori et al., 2012^1 [151]; Bansal et al., 2020^2 [147]; Bansal et al., 2022^3 [148]; Nasrin et al., 2021a^4 [74]
	Omeprazole	-	-	0.57^1, 0.25^2, 0.21^3	0.21^3	Bansal et al., 2020^1 [147]; Bansal et al., 2022^2 [148]; Nasrin et al., 2021a^3 [74]
	Dextromethorphan	23^1	-	1.3^2, 0.56^3, 0.77^4	0.28^4	Yamaori et al., 2011a^1 [149]; Bansal et al., 2020^2 [147]; Bansal et al., 2022^3 [148]; Nasrin et al., 2011a^4 [74]
	Diltiazem	-	>50	-	-	Yamaori et al., 2011b [150]
	Midazolam	-	-	1.3	-	Bansal et al., 2020 [147]
	Testosterone	-	-	0.57	-	Bansal et al., 2022 [148]

* r, recombinant enzyme from overexpressing cell line microsomes; HLM, human liver microsomes. ** Values are the mean in µM. ^╪ Values were corrected for non-specific binding of cannabinoids in respective experimental systems. ^# AMMC, 3-[2-(N,N-diethyl-N-methylammonium)ethyl]-7-methoxy-4-methylcoumarin. Numerical superscripts identify the reference associated with the kinetic data value. Dashes indicate that values were not determined.

Table 2. Inactivation kinetic constants of time dependent inhibition of recombinant CYPs and HLM.

Microsomal Protein*	Substrate	THC			CBD			7-OH-CBD			CBN			Reference
		KI (µM)	kinact (min^−1)	kinact/KI (min^−1.µM^−1)	KI,U (µM)	kinact (min^−1)	kinact/KI,U (min^−1.µM^−1)	KI,U (µM)	kinact (min^−1)	kinact/KI,U (min^−1.µM^−1)	KI (µM)	kinact (min^−1)	kinact/KI (min^−1.µM^−1)
rCYP1A1	7-Ethoxyresorufin	1.2^a	0.023	0.019^a	5.9^a	0.32	0.054^a	-	-	-	0.090^a	0.019	0.21^a	Yamaori et al., 2010 [146]
rCYP1A2	7-Ethoxyresorufin	-	-	-	0.59^a	0.11	0.19^a	-	-	-	-	-	-	Yamaori et al., 2010 [146]
	Phenacetin	-	-	-	0.11	0.070	0.70	-	-	-	-	-	-	Bansal et al., 2020 [147]
rCYP1B1	7-Ethoxyresorufin	-	-	-	3.1^a	0.027	0.0087^a	-	-	-	-	-	-	Yamaori et al., 2010 [146]
rCYP2A6	Coumarin	0.86^a	0.017	0.020^a	-	-	-	-	-	-	1.0^a	0.0091	0.0090^a	Yamaori et al., 2011b [150]; Yamaori et al., 2011c [152]
HLM	Diclofenac	-	-	-	0.070	0.035	0.62	0.67	0.063	0.10	-	-	-	Bansal et al., 2020 [147]; Bansal et al., 2022 [148]
HLM	Testosterone	-	-	-	0.11	0.078	0.79	1.0	0.13	0.14	-	-	-	Bansal et al., 2020 [147]; Bansal et al., 2022 [148]

*r, recombinant enzyme from overexpressing cell line microsomes; HLM, human liver microsomes. ^aK_I values were not corrected for non-specific binding. Dashes indicate that values were not determined.

Table 3. Reversible inhibition of recombinant CYPs and HLM by the metabolites of THC and CBD.

Microsomal Protein*	Substrate	11-OH-THC		THC-COOH	THC-COO-Gluc		7-OH-CBD
		IC50,u^a	Ki,u^a	IC50,u^a,b	IC50,u^a	Ki,u^a	IC50,u^a,b	References
rCYP2B6	Bupropion	0.55	0.086	-	5.5	0.90	-	Nasrin et al., 2021a [74]
rCYP2C9	Diclofenac	0.30	0.057	-	15	2.1	-	Nasrin et al., 2021a [74]
rCYP2D6	Dextromethorphan	0.34	0.15	-	7.8	2.3	-	Nasrin et al., 2021a [74]
HLM	Phenacetin	1.8	-	>50^1	-	-	>13	Bansal et al., 2022 [148]
	Bupropion	0.77	0.26	-	5.3	1.1	0.34	Nasrin et al., 2021a [74]
	Bupropion	0.32	-	-	-	-	-	Bansal et al., 2022 [148]
	Amodiaquine	3.7	-	-	-	-	1.0	Bansal et al., 2022 [148]
	Diclofenac	0.45	0.21	-	18	3.4	0.43	Nasrin et al., 2021a [74]
	Diclofenac	0.36^1	-	>50^2	-	-	-	Bansal et al., 2022^1 [148]; Bansal et al., 2020^2 [147]
	Omeprazole	1.8^1	-	>50^2	-	-	0.82^1	Bansal et al., 2022^1 [148]; Bansal et al., 2020^2 [147]
	Dextromethorphan	0.61	0.32	-	13	2.7	2.5	Nasrin et al., 2021a [74]
	Dextromethorphan	5.3^1	-	>50^2	-	-	-	Bansal et al., 2022^1 [148]; Bansal et al., 2020^2 [147]
	Testosterone	>6.7^1	-	-	>50^2	-	0.80^1	Bansal et al., 2022^1 [148]; Bansal et al., 2020^2 [147]

* r, recombinant enzyme from overexpressing cell line microsomes; HKM, HLM, human liver microsomes.

^aIC_50,u and K_i,u values are the mean in µM and were corrected for non-specific binding of cannabinoids in their respective experimental systems.

^bNo K_i values were reported for this THC metabolite.

Numerical superscripts identify the reference associated with the kinetic data value. Dashes indicate that values were not determined.

Table 4. Reversible inhibition of recombinant CYPs and HLM by CBD.

Microsomal Protein*	Probe Substrate	IC50**	Ki**	IC50,u**^,╪	Ki,u**^,╪	References
rCYP1A1	7-Ethoxyresorufin	-	0.16	-	-	Yamaori et al., 2010 [146]
rCYP1A2	7-Ethoxyresorufin	-	2.7	-	-	Yamaori et al., 2010 [146]
	Phenacetin	-	-	0.13	0.12	Nasrin et al., 2021a [74]
rCYP1B1	7-Ethoxyresorufin	-	3.6	-	-	Yamaori et al., 2010 [146]
rCYP2A6	Coumarin	-	55	-	-	Yamaori et al., 2011c [152]
rCYP2B6	7-Benzoxyresorufin	-	0.70	-	-0.068^1, 3.4^2	Yamaori et al., 2011c [152]
	Bupropion	-	-	0.13^1, 6.2^2	-	Nasrin et al., 20211^1[74]; Doohan et al., 2021^2 [153]
rCYP2C9	(S)-warfarin	2.7	0.95	-	-	Yamaori et al., 2012 [151]
	Tolbutamide	-	-	2.5	1.3	Doohan et al., 2021 [153]
	Diclofenac	2.7^1	2.3^1	0.22^2	0.093^2	Yamaori et al., 2012^1 [151]; Nasrin et al., 2021a^2 [74]
rCYP2C19	(S)-Mephenytoin	2.5	0.79	-	-	Jiang et al., 2013 [102]
	Omeprazole	1.6^1	-	0.16^2, 2.1^3	0.050^2, 1.1^3	Jiang et al., 2013^1 [102]; Nasrin et al., 2021a^2 [74]; Doohan et al., 2021^3 [153]
rCYP2D6	Dextromethorphan	6.0^1	-	0.19^2	0.074^2	Yamaori et al., 2011a^1 [149]; Nasrin et al., 2021a^2 [74]
	AMMC^#	6.5	-	-	-	Yamaori et al., 2011a [149]
rCYP2E1	Chlorzoxazone	-	-	0.037	0.021	Nasrin et al., 2021a [74]
rCYP3A4	Diltiazem	12	1.0	-	-	Yamaori et al., 2011b [150]
	Midazolam	-	-	0.19	0.093	Nasrin et al., 2021a [74]
rCYP3A5	Diltiazem	1.7	0.20	-	-	Yamaori et al., 2011b [150]
rCYP3A7	Diltiazem	25	12	-	-	Yamaori et al., 2011b [150]
HLM	7-Ethoxyresorufin	-	1.8	-	-	Yamaori et al., 2010 [146]
	Phenacetin	-	-	0.45^1, 0.11^2, 0.67^3	0.21^3	Bansal et al., 2020^1 [147]; Bansal et al., 2022^2 [148]; Nasrin et al., 2021a^3 [74]
	Bupropion	-	-	0.050^1, 0.26^2	0.22^2	Bansal et al., 2022^1 [148]; Nasrin et al., 2021a^2 [74]
	Amodiaquine	-	-	0.28	-	Bansal et al., 2022 [148]
	(S)-warfarin	4.8	5.6	-	-	Yamaori et al., 2012 [151]
	Diclofenac	13^1	9.9^1	0.17^2, 0.040^3, 0.48^4	0.19^4	Yamaori et al., 2012^1 [151]; Bansal et al., 2020^2 [147]; Bansal et al., 2022^3 [148]; Nasrin et al., 2021a^4 [74]
	Omeprazole	-	-	0.30^1, 0.080^2, 0.36^3	0.092^3	Bansal et al., 2020^1 [147]; Bansal et al., 2022^2 [148]; Nasrin et al., 2021a^3 [74]
	Dextromethorphan	4.0^1	-	0.95^2, 0.24^3, 0.52^4	0.31^4	Yamaori et al., 2011a^1 [149]; Bansal et al., 2020^2 [147]; Bansal et al., 2022^3 [148]; Nasrin et al., 2021a^4 [74]
	Chlorzoxazone	-	-	0.14	0.058	Nasrin et al., 2021a [74]
	Diltiazem	9.2^1	6.1^2	-	-	Yamaori et al., 2012^1 [151]; Yamaori et al., 2011b^2 [150]
	Midazolam	-	-	0.45	0.22	Nasrin et al., 2021a [74]
	Testosterone	-	-	0.38^1, 0.090^2	-	Bansal et al., 2020^1 [147]; Bansal et al., 2022^2 [148]

* r, recombinant enzyme from overexpressing cell line microsomes; HLM, human liver microsomes.

** Values are the mean in µM.

^╪Values were corrected for non-specific binding of cannabinoids in their respective experimental systems.

^#AMMC, 3-[2-(N,N-diethyl-N-methylammonium)ethyl]-7-methoxy-4-methylcoumarin

Numerical superscripts identify the reference associated with the kinetic data value. Dashes indicate that values were not determined.

Table 5. IC₅₀ and K_i values of cannabinoids against major non-CYP450 enzymes in recombinant enzymes, HKM and HLM.

Enzyme screened	Substrate	Assay system^b	IC50,u^a or Ki,u^a			References
			THC	CBD	CBN
			Ki,u^a
CES1	Oseltamivir phosphate	rCES1	0.54^c	0.97^c	0.26^c	Qian et al., 2019b [171]
	Methylphenidate	rCES1	0.031	0.091	-	Qian et al., 2022 [172]
			IC50,u^a
UGT1A9	Propofol	rUGT1A9	0.45	0.12	0.51	Nasrin et al., 2021b [173] Nasrin et al., 2021b [173] Nasrin et al., 2021b [173]
		HKM	0.64	0.34	0.90
		HLM	1.4	1.0	2.9
	Furosemide	rUGT1A9	0.33	0.090	0.78
		HKM	0.54	0.22	1.9
		HLM	1.5	1.5	3.1
	Acetaminophen	rUGT1A9	0.49	0.073	0.59
		HKM	0.79	0.24	2.6
		HLM	1.4	0.64	2.8
UGT2B7/1A9	Ethanol	HLM	-	3.72^c	-	Al Saabi et al., 2013 [178]
UGT2B7	Zidovudine (AZT)	rUGT2B7	1.4	0.82	4.2	Nasrin et al., 2021b [173] Nasrin et al., 2021b [173] Nasrin et al., 2021b [173]
		HKM	2.6	2.2	6.9
		HLM	2.8	1.5	5.5
UGT2B4	Codeine	rUGT2B4	0.47	0.22	- - -
		HKM	2.9	2.5
		HLM	0.61	0.40
UGT1A6	Serotonin	rUGT1A6	- - -	0.40	- - -
		HKM		1.0
		HLM		1.4

^aIC_50,u and K_i,u values are the mean in µM and were corrected for non-specific binding of cannabinoids in their respective experimental systems unless otherwise indicated.

^br, recombinant enzyme from overexpressing cell line microsomes; HKM, human kidney microsomes; HLM, human liver microsomes.

^cIC₅₀ or K_i values were not corrected for non-specific binding.

Dashes indicate that values were not determined.

Yamaori S, Kushihara M, Yamamoto I, et al. Characterization of major phytocannabinoids, cannabidiol and cannabinol, as isoform-selective and potent inhibitors of human CYP1 enzymes. Biochem Pharmacol. 2010;79(11):1691–1698.

 Google Scholar

Nasrin S, Watson CJW, Perez-Paramo YX, et al. Cannabinoid metabolites as inhibitors of major hepatic CYP450 enzymes, with implications for cannabis-drug interactions. Drug Metab Dispos. 2021a;49(12):1070–1080.

 Google Scholar

Yamaori S, Okamoto Y, Yamamoto I, et al. Cannabidiol, a major phytocannabinoid, as a potent atypical inhibitor for CYP2D6. Drug Metab Dispos. 2011c;39(11):2049–2056.

 Google Scholar

Yamaori S, Koeda K, Kushihara M, et al. Comparison in the in vitro inhibitory effects of major phytocannabinoids and polycyclic aromatic hydrocarbons contained in marijuana smoke on cytochrome P450 2C9 activity. Drug Metab Pharmacokinet. 2012;27(3):294–300.

 Google Scholar

Jiang R, Yamaori S, Okamoto Y, et al. Cannabidiol is a potent inhibitor of the catalytic activity of cytochrome P450 2C19. Drug Metab Pharmacokinet. 2013;28(4):332–338.

 Google Scholar

Yamaori S, Maeda C, Yamamoto I, et al. Differential inhibition of human cytochrome P450 2A6 and 2B6 by major phytocannabinoids. Forensic Toxicol. 2011a;29(2):117–124.

 Google Scholar

Yamaori S, Ebisawa J, Okushima Y, et al. Potent inhibition of human cytochrome P450 3A isoforms by cannabidiol: role of phenolic hydroxyl groups in the resorcinol moiety. Life Sci. 2011b;88(15–16):730–736.

 Google Scholar

Bansal S, Maharao N, Paine MF, et al. Predicting the potential for cannabinoids to precipitate pharmacokinetic drug interactions via reversible inhibition or inactivation of major cytochromes P450. Drug Metab Dispos. 2020;48(10):1008–1017.

 Google Scholar

Bansal S, Paine MF, Unadkat JD. Comprehensive predictions of cytochrome P450 (CYP)-mediated in vivo cannabinoid-drug interactions based on reversible and time-dependent CYP inhibition in human liver microsomes. Drug Metab Dispos. 2022;50(4):DMD-AR-2021–000734.

 Google Scholar

Doohan PT, Oldfield LD, Arnold JC, et al. Cannabinoid interactions with cytochrome P450 drug metabolism: a full-spectrum characterization. Aaps j. 2021;23(4):91.

 Google Scholar

Qian Y, Wang X, Markowitz JS. In vitro inhibition of carboxylesterase 1 by major cannabinoids and selected metabolites. Drug Metab Dispos. 2019b;47(5):465–472.

 Google Scholar

Qian Y, Markowitz JS. Prediction of carboxylesterase 1 (CES1)-mediated in vivo drug interaction between methylphenidate and cannabinoids using static and physiologically based pharmacokinetic models. Drug Metab Dispos. 2022;50(7):968.

 Google Scholar

Nasrin S, Watson CJW, Bardhi K, et al., Inhibition of UDP-glucuronosyltransferase enzymes by major cannabinoids and their metabolites. Drug Metab Dispos. 2021b;49(12):1081–1089.

 Google Scholar

Al Saabi A, Allorge D, Sauvage FL, et al. Involvement of UDP-glucuronosyltransferases UGT1A9 and UGT2B7 in ethanol glucuronidation, and interactions with common drugs of abuse. Drug Metab Dispos. 2013;41(3):568–574.

 Google Scholar