Valerian: No Evidence for Clinically Relevant Interactions

Table 1

Potential pharmacokinetic interactions of valerian according to the published literature. The conclusions by the respective authors, the ratings given by MedIQ (http://www.mediq.ch, a Swiss independent interaction data base, which is structured according to mechanisms of interaction and includes herbal drugs), and the conclusions regarding the potential of clinically relevant interactions based on a critical analysis of the published studies are reported.

Metabolic pathway	In vitro studies	In vivo studies	Interaction potential (according to medIQ database [33])	Indication for a clinically relevant interaction
CYP 1A2	No effect [34]	No effect [35]		None
CYP 2D6	Induction [36]	No effect [35, 37]	Weak inhibitor	None
CYP 2E1		No effect [35]		None
CYP 3A4	Induction [36, 38]	No effect [34, 35, 37]	Weak inductor	None
P-glycoprotein	Weak inhibition? [39, 40]	No data available	Weak inhibitor	None
UGT 1A1	Weak inhibition? [41, 42]	No data available	Weak inhibitor	None
UGT 2B7	Weak inhibition? [41]	No data available	Weak inhibitor	None

CYP: cytochrome P450; UGT: uridine 5′-diphosphate glucuronosyltransferase.