A randomized, double blind, placebo-controlled, prospective clinical study to demonstrate clinical efficacy of a fixed valerian hops extract combination (Ze 91019) in patients suffering from non-organic sleep disorder.
Phytother Res. 2007 Sep;21(9):847-51. PMID: 17486686
Valerian and hops are traditionally used as sleep aids. Since the fixed extract combination (Ze 91019) as a whole is considered the active compound, the clinical efficacy must be demonstrated for this extract combination. The present clinical study aimed to demonstrate superiority of the fixed extract combination in comparison with placebo in patients suffering from non-organic insomnia (ICD 10, F 51.0-51.2). Objective sleep parameters were registered by means of a transportable home recorder system (QUISI). The primary outcome was the reduction in sleep latency (SL2) which had to be prolonged at baseline (>/=30 min) as an inclusion criteria. The treatment period lasted for 4 weeks with either placebo, single valerian extract (Ze 911) or the fixed valerian hops extract combination (Ze 91019). The amount of the single valerian extract was identical to that amount contained in the fixed extract combination, i.e. 500 mg valerian extract siccum. In the extract combination 120 mg hops extract siccum was added. Both the extracts were prepared with 45% methanol m/m with a drug-extract ratio of 5.3:1 (valerian) and 6.6:1 (hops), respectively. The fixed extract combination was significantly superior to the placebo in reducing the sleep latency whilst the single valerian extract failed to be superior to the placebo. The result underlined the plausibility for adding hops extract to the valerian extract.