Hops contribute to the clinical efficacy of a fixed valerian hops extract combination in patients with primary insomnia. A placebo controlled, double-blind, randomized and prospective clinical trial

Valerian and hops are traditionally used as sleep aids. Valerian extract acts like adenosine which is a sleep promoting endogenous transmitter. Hops, on the other hand, influence the circadian entrainment like melatonin. Therefore the combination of both of the extracts seems meaningful. However, as the fixed valerian and hops extract combination Ze 91019 has to be seen as the pharmacological active principle, the clinical efficacy must be demonstrated for this combination. Pharmacodynamic actions [1] as well as efficacy in an uncontrolled study in patients suffering from non-organic sleep disorders [2] have already been reported. In the present study the influence of placebo, valerian extract (Ze 911) and the fixed extract combination (Ze 91019) was investigated in patients suffering from sleep disorders (ICD10: F 51.0, F 51.2). The primary outcome was the reduction of sleep onset latency (SL2) which has to be prolonged at baseline (³ 30min, inclusion criteria). The hypnograms to calculate the objective sleep parameters were recorded with mobile technique (QUISI) twice before including the patient in the study. Treatment period lasted for 4 weeks with placebo, valerian extract or the fixed extract combination. The amount of the pure valerian extract (500mg valerian extract siccum: Ze 911) corresponded to that amount which is contained in the fixed combination (500mg valerian extract siccum plus 120mg hops extract siccum: Ze 91019). Both of the extracts were prepared with 45% methanol m/m with a DER for valerian: 5–8: 1 and for hops 7–10:1.

The fixed extract combination Ze 91019 was significantly superior to placebo in reducing the originally prolonged sleep onset latency whilst the pure valerian extract failed to be superior. With this study the additional effect of hops was demonstrated (plausibility check).

[1] Vonderheid-Guth B et al.: Pharmacodynamic effects of valerian and hops extract combination (Ze 91019 on the quantitativetopographical EEG in healthy volunteers. Eur J Med Res 2000; 5: 139–144.

[2] Füssel A. et al.: Effect of a fixed valerian-hop extract combination (Ze 91019) on sleep polygraphy in patients with non-organic insomnia. Eur J Med Res 2000; 5: 385–389.