Hyoscine

Two recently published studies add to the growing body of evidence [1] that valerian improves sleep quality [2] without impairing morning performance. [3] The earlier of the two studies examined the influence of valerian treatment on reaction time, alertness and concentration in healthy people. [3] The randomized, controlled, double-blind trial engaged 102 male and female volunteers. The effect was first examined the morning after a single evening dose of valerian root extract (600 mg), flunitrazepam (1 mg) or placebo, and then after two weeks of evening administration of valerian and placebo. The primary criterion was reaction time (RT) measured with the Vienna Determination Test. Secondary criteria included an alertness test, a tracking test (two-handed co-ordination), sleep quality and safety criteria. The single administration of valerian did not impair the reaction abilities, concentration and co-ordination compared to placebo. This was not the case for the flunitrazepam (a benzodiazepine drug) which ca used a deterioration relative to placebo.

Results after 14 days confirmed that there was no difference between valerian and placebo in terms of effect on reaction time and other psychometric test results. There was a trend towards improved sleep quality for valerian over placebo which did not achieve statistical significance. In terms of adverse effects, valerian and placebo were not significantly different.

The second study, published earlier this year was a carefully designed study to assess the short-term (single dose) and long-term (14 days with multiple dosage) effects of a valerian extract on both objective and subjective sleep parameters. [2] The investigation was performed as a randomized, double-blind, placebo-controlled, cross-over study. Sixteen patients (4 male, 12 female) with previously established insomnia were included in the study. The main inclusion criteria were reported primary insomnia, which was confirmed by polysomnographic recording, and the absence of acute diseases. During the study, patients underwent 8 polysomnographic recordings: 2 recordings (baseline and study night) at each time point when the short- and long-term effects of placebo and valerian were tested. The target variable of the study was sleep efficiency. Other parameters describing objective and subjective parameters such as sleep quality, morning feeling, daytime performance, sleep latency (time to fall asleep) and sleep period time, were assessed. After a single dose of valerian, no effects on sleep structure and subjective sleep assessment were observed. After multiple-dose treatment, sleep efficiency showed a significant increase for both placebo and valerian in comparison with baseline polysomnography. However, there were significant differences between valerian and placebo for parameters describing slow-wave sleep (SWS). In comparison with the placebo, slow-wave sleep latency was reduced after administration of valerian (21.3 vs. 13.5 mm respectively, p[less than]0.05). The SWS percentage of time in bed was increased after long-term valerian treatment in comparison to baseline (9.8 vs. 8.1% respectively, p[less than]0.05). A remarkable finding of the study was the extremely low number of adverse events during the valerian treatment periods (3 vs. 18 in the placebo period). The authors concluded that treatment with a valerian extract demonstrated positive effects on the sleep structure and sleep perception of insomnia pat ients and can therefore be recommended for the treatment of patients with mild psychophysiological insomnia.

Commentary

The sleep quality study revealed two interesting findings which should not surprise natural therapists familiar with the use of valerian. The first is that valerian begins to significantly improve sleep quality only after continuous short-term use. A single dose before bed is unlikely to improve sleep quality (other than a placebo effect); valerian's effect on sleep is a cumulative effect which takes repeated doses over several days. Part of this cumulative effect could be a reduction in stress and anxiety during the day which flows on to improved sleep. The second finding was the remarkable safety of valerian, with much fewer adverse events than placebo. This might have resulted from its anxiolytic influence.

Despite this high safety profile of valerian, it is much maligned in the scientific literature. It is almost as if researchers find it difficult to comprehend that a proven anxiolytic and sleep-promoting agent is free of damaging effects on the nervous system. A case in point is a letter published in the International Journal of Clinical Pharmacology and Therapeutics. [4] The letter, entitled An assessment of the delayed effects associated with valerian overdose purports to describe 24 cases of overdose of valerian, with symptoms of central nervous system depression and anticholinergic poisoning. One patient required ventilatory support and developed aspiration pneumonia. These are serious findings that will doubtlessly be recirculated in the scientific literature as one example of the "dangers" of taking herbs safely used every day by thousands, if not millions, of people. But a close reading of the letter shows that the culprit was not valerian at all. As well as containing valerian, the product contained the drugs hyoscine hydrobromide and cyproheptadine hydrochloride, which would readily explain the symptoms observed on overdose. Another letter published in the Journal of the American Medical Association attributes surprising benzodiazepine-like withdrawal symptoms in one patient to his use of valerian. [5] This contrasts strongly with the findings of controlled clinical trials, such as the two described above.

References

(1.) Mills S, Bone K. Principles and Practice of Phytotherapy: Modern Herbal Medicine. Edinburgh: Churchill Livingstone, 2000: pp 584-586

(2.) Donath F, Quispe S, Diefenbach K et al. Critical evaluation of the effect of valerian extract on sleep structure and sleep quality. Pharmacopaychiatry 2000; 33(2): 47.53

(3.) Kuhlmann J, Berger W, Podzuweit H et al. The influence of valerian treatment en reaction time, alertness and concentration" in volunteers. Pharmacapsychiatry 1959; 32(6): 236-241

(4.) Chan TYK. An assessment of the delayed effects associated with valerian overdose. Int J Clin Pharmacol Ther 1998; 36(10): 569

(5.) Gorges HP, Varia I, Doraiswamy PM. Cardiac complications and delirium associated with valerian coot withdrawal. JAMA 1998; 280(18); 1566-1567

COPYRIGHT 2001 The Townsend Letter Group
COPYRIGHT 2001 Gale Group