Table 2.

In vivo pharmacokinetic drug–drug interaction study of Sativex [38].

Product	Population Studied	Interacting Drugs	Results
THC+CBD mucosal spray (Sativex), 4 sprays	Healthy Adults (n = 36)	Rifampicin 600 mg (CYP3A, CYP2C19 inducer)	THC: 36% decrease 11-OH-THC: 87% decrease
		Ketoconazole 400 mg (CYP3A inhibitor)	THC: 27% increase 11-OH-THC: 204% increase
		Omeprazole 40 mg (CYP2C19 inhibitor)	No change in THC or 11-OH-THC

All participants in the study reported a serious adverse effect when THC was combined with ketoconazole, primarily neuropsychiatric in nature.