Valerian The
Valeriana genus contains hundreds of species; V.
officinalis is commonly used in Europe and North America. The root or rhizome is used medicinally. It has a distinct and disagreeable odor when dried.
Uses and Benefits: Valerian is considered to be a mild sedative-hypnotic herb, primarily promoted for insomnia in the U.S. It is a popular hypnotic and daytime sedative in many European countries. Traditionally, valerian has been used as a gastrointestinal antispasmodic and for a wide variety of physical conditions associated with anxiety, stress, and nervous complaints.
Pharmacology: Numerous constituents have been identified, many of which have pharmacologic properties. The volatile oil, consisting of monoterpenes and sesquiterpenes such as valerenic acid, is one of the more biologically active components found in valerian rooF-4 Valepotriates, such as valtrate and isovaleric acid, are pharmacologically active but very unstable, and are unlikely to be in finished products or absorbed systemically. Alkaloids, amino acids, and other compounds may also contribute to activity, but no single constituent has been shown to account for all of valerian's effects. Inhibitory GABA receptors are stimulated in the eNS by valerian extract, but the precise action is unknown and may involve more than one mechanism.
Clinical Trials:A systematic review of the worldwide literature identified nine randomized, double-blind, placebo-controlled trials, conducted in Europe, of valerian mono-preparations. Overall interpretation of the results of these trials was difficult because of the inconsistent methodologic quality and study designs, and variable results. Based on questionnaires, polysomnography evaluations, or crude wrist meters, clinical improvements in sleep onset and/or sleep quality were observed in five trials, while effects were equivalent to placebo in four trials. Favorable EEG changes resulting from valerian were demonstrated in two of four studies. While two high-quality trials contained more than 100 patients (both with positive results), most studies were much smaller, containing 8-14 patients each. 8 Clinical effects were usually observed within 1-2 days in shorter or acute-dose trials, but beneficial effects on sleep quality became statistically significant only after 4 weeks of treatment in one of the larger and better quality trials with 121 patients,
Adverse Effects:Side effects were similar to placebo in the controlled trials. In contrast to benzodiazepines, valerian does not appear to cause a hangover effect or adversely affect reaction time, alertness, or concentration the following day although slight impairment of vigilance was found 1-2 hours after administration in one study. Dependence and withdrawal reactions have not been observed with usual doses, but these responses have not been adequately evaluated.
In case reports, hepatotoxicity has been associated with herbal products that contain valerian, but most of these reports involve combinations with known or suspected hepatotoxic herbs. One patient taking excessive doses of a U.S. valerian product (530 mg to 2 g per dose, 5 times daily for many years) developed high-output cardiac failure and delirium after discontinuing the herbal medicine while undergoing an open lung biopsy under (jeneral anesthesia. His condition slowly reversed with midazolam, raising the possibility of a valerian "withdrawal reaction" from excessive chronic dosing. Valerian appears to be relatively safe in acute overdose cases. A suicide attempt by an 18-year-old college student who ingested 40-50 valerian capsules resulted in lion-life-threatening effects such as fatigue, lightheadedness, body pains, and tremor, which all resolved within 24 hours.
Side Effects and Interactions: There are no documented drug interactions. Valerian did not increase impairment due to alcohol according to one European placebo-controlled trial. However, it is prudent to warn patients not to mix excessive doses of valerian with CNSdepressant drugs.
Cautions: Valerian byproducts are cytotoxic and mutagenic
in vitro. It is doubtful that these effects are relevant for humans,however, as the most cytotoxic products (valepotriates) are very unstable and may not be present in marketed products; furthermore, they deteriorate rapidly in the intestines and are poorly absorbed. In addition, chronic high doses of valepotriates in animals did not produce tumors, and oral administration did not produce teratogenic effects. However, there is a lack of clinical data for pregnant and nursing women, and therefore valerian is not recommended for these subjects.
Preparations & Doses: Traditionally, 2-3 g/day of dried root or rhizome (usually as an infusion or extract) is taken as needed 2-3 times per day as a sedative, or before bedtime for insomnia. The dose for insomnia used in the controlled clinical trials ranged from 400 to 900 mg of an aqueous or ethanolic root extract, roughly equivalent to 1.5-3 g of dried herb, given 1/2 to 1 hour before bedtime. The only product evaluated in these trials that is currently distributed in the U.S. is Sedonium (Lichtwer Pharma); it was not effective in a recent trial. American products vary widely and are not uniform in content. Some contain whole herb, while others contain a variety of different proprietary extracts. Some valerian products are standardized to valerenic acid, which is a useful marker compound for
V. officinalis as it is not found in other species.
Summary Evaluation:Valerian root has traditionally been used as a mild sedative-hypnotic, but evidence from randomized, controlled trials is inconclusive. Valerian is well tolerated and with low abuse potential in usual therapeutic doses. It is not unreasonable for patients to try valerian root as a mild sedative or hypnotic, especially for those who want a non-addictive alternative to drugs such as benzodiazepines. However, valerian's efficacy has not been demonstrated beyond a reasonable doubt, especially with short-term use.
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