title: Pharmacokinetics of valerenic acid after single and multiple doses of valerian in older women.
abstract: Insomnia is a commonly reported clinical problem with as many as 50% of older adults reporting difficulty in falling and/or remaining asleep. Valerian (Valeriana officinalis) is a commonly used herb that has been advocated for promoting sleep. Valerenic acid is used as a marker for quantitative analysis of valerian products with evidence of pharmacological activity relevant to the hypnotic effects of valerian. The objective of this study was to determine the pharmacokinetics of valerenic acid in a group of elderly women after receiving a single nightly valerian dose and after 2 weeks of valerian dosing. There was not a statistically significant difference in the average peak concentration (C(max)), time to maximum concentration (T(max)) area under the time curve (AUC), elimination half-life (T(1/2)) and oral clearance after a single dose compared with multiple dosing. There was considerable inter- and intra-subject variability in the pharmacokinetic parameters. C(max) and AUC deceased and T(1/2) increased with increased body weight. The variability between the capsules was extremely low: 2.2%, 1.4% and 1.4%, for hydroxyvalerenic acid, acetoxyvalerenic acid and valerenic acid, respectively. In conclusion, large variability in the pharmacokinetics of valerenic acid may contribute to the inconsistencies in the effect of valerian as a sleep aid.
authors.affiliation: Department of Pharmacy, Schools of Pharmacy, University of Washington, Seattle, WA 98195, USA. gaila@u.washington.edu
authors.forename: Gail D
authors.initials: GD
authors.lastname: Anderson
authors.forename: Gary W
authors.initials: GW
authors.lastname: Elmer
authors.forename: Diana M
authors.initials: DM
authors.lastname: Taibi
authors.forename: Michael V
authors.initials: MV
authors.lastname: Vitiello
authors.forename: Eric
authors.initials: E
authors.lastname: Kantor
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Kalhorn
authors.forename: William N
authors.initials: WN
authors.lastname: Howald
authors.forename: Suzanne
authors.initials: S
authors.lastname: Barsness
authors.forename: Carol A
authors.initials: CA
authors.lastname: Landis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001835:Body Weight; D005260:Female; D006207:Half-Life; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007192:Indenes / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D008875:Middle Aged; D009822:Oils, Volatile / Q000008:administration & dosage / Q000493:pharmacokinetics; D008517:Phytotherapy; D012717:Sesquiterpenes / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy*; D014632:Valerian / Q000737:chemistry*
chemical_list: D006993:Hypnotics and Sedatives; D007192:Indenes; D009822:Oils, Volatile; D012717:Sesquiterpenes; C037133:valerenic acid