THERAPY

Kava each day keeps the blues away

-Kate Palmer-

For the past 30 years, benzodiazepines have been the mainstay of treatment for anxiety and other stress~related symptoms. Although effective, these drugs are associated with a number of adverse effects which limit their use, including their ability to induce tolerance and dependence. The search for alternative anxiolytics has taken researchers along a number of paths, including the assessment of several 'natural' products that are anecdotally renown for their anxiolytic effects. The effects of one such traditional medicine, kava (a herb found in the Pacific islands), have been investigated by US researchers. The results of these studies into the effects of kava in adults with daily stress and anxiety were presented at the Second World Congress on Stress [Melbourne, Australia; October 1998].

Kava is obtained from the plant Piper methysticum Forst, which grows exclusively in the islands of the Pacific, such as Fiji and Vanuatu. It has been used ceremonially for over 3000 years to induce a general state of relaxation. Traditionally, the roots of the kava plant are harvested, dried and ground with water to produce a muddy tasting drink. A number of companies now produce kava lactones in capsule and tablet form.

Assessing efficacy and safety A double-blind, placebo-controlled, randomised

study to assess the safety and efficacy of kava lactones in adults experiencing daily stress and anxiety was conducted by Professor Nirbhay Singh and colleagues from the Virginia Commonwealth University, Richmond, US.

The study enrolled 67 adults aged between 18 and 68 years. These patients had elevated levels of daily stress and anxiety, as evidenced by a score of one standard deviation above the mean on the State-Trait Anxiety Inventory. Patients with endogenous depression, psychoses or dementia and those taking any prescription medication that could possibly interact with kava lactones, such as antipsychotics, anti­depressants or anxiolytics, were excluded from the study.

Patients received either 4 capsules of a nonprescrip­tion brand of kava ['Kavatro!'], equivalent to a total of 240mg of kava lactones, or placebo, each day for 4 weeks. 60 patients completed the study (29 and 31 recipients of kava and placebo, respectively).

Calming with kava During the course of the study, kava recipients

showed a decrease in stress and anxiety symptoms, as measured by the Weekly Stress Index. In comparison, placebo recipients had little change in these symptoms. The mean decrease in symptoms for kava recipients was significant compared with that for placebo recipients by the second week of treatment and remained so until the end of the study.

Kava recipients showed decreases in the ratings of each of the daily stressor clusters that were measured. These included interpersonal problems, personal competency, cognitive stressors, environmental stressors and varied stressors of urban life. Kava recipients also showed a reduction in the State Anxiety measure.

Encouragingly, the administration of kava was not associated with any adverse effects, said Professor Singh. About 27 parameters that could have been construed as indicating adverse effects of treatment were assessed during the trial. There was no worsening of these parameters in either treatment group.

1173-832419811167.000111$01.00° Adlalm.matlonal Limited 1988. All rlghta raHrVed

No dosage differences In light of the positive findings obtained in their

initial study, Professor Singh's group has conducted another investigation into the anxiolytic effects of kava. This placebo-controlled study examined the effects of 2 dosages of kava lactones administered for 4 weeks. 86 patients with stress and anxiety were treated with 240 or 360 mg/day of kava lactones or placebo. Professor Singh presented a preliminary analysis of the study results which indicated that both kava dosages were more effective than placebo, but that there was no difference in efficacy between the high and low dosage.

As well as being an effective anxiolytic, kava may be useful for treating women with premenstrual syndrome (PMS). Interestingly, there was a reduction in the anxiety component of PMS and the pain associated with menstruation in women receiving kava during the initial study, said Professor Singh. The potential for kava in this indication will be investigated further in a study starting in early 1999, he added.

Better than benzodiazepines? Kava appears to be an effective treatment for patients

with daily stress and anxiety and has no major adverse effects, concluded Professor Singh. Importantly, there was also no indication of tolerance or psychological addiction to kava therapy. However, he did caution that adverse effects have been reported with the ingestion of large doses of kava in Pacific islanders. The main adverse effect that has been reported in these individuals is a skin condition characterised by scaling and yellow discolouration. This effect is reversible with discontinuation of the intake of kava.

Given the anxiolytic efficacy of kava and the fact that it is relatively inexpensive, Professor Singh speculated that it could represent a viable alternative to benzodiazepine treatment. However, further studies of the product are needed to clarify its mechanism of action and its efficacy compared with other treatments, he added.

Cultural differences Despite the apparent promise of kava, Professor

Singh warned that the product should not be regarded as a 'magic bullet' to a stress-free life. Kava is traditionally used to induce relaxation as part of a culture that is relatively more relaxed that many Western cultures, he said. Our approach to reducing stress and anxiety in the Western world should be more holistic involving lifestyle changes as much as relying on anxiolytic medication, he added.

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12 THERAPY

Conservation and standardisation Other important issues to be addressed before the

more extensive use of kava can be considered are those of conservation and standardisation, said Professor Singh. Recently, there has been an explosion of interest in the therapeutic use of kava, particularly in the US. Consequently, demand for the raw product is high.

Given that it takes 5 years for kava plants to reach maturity, some measures need to be put in place to ensure an adequate and sustainable source of kava is available. There is a real possibility that Fijian kava sources will be exhausted in a few years time and the viability of growing kava plants commercially in Hawaii is being investigated.

A second important issue for the therapeutic use of kava is that of standardisation, said Professor Singh. Currently, kava is available without a prescription and so does not need regulatory approval. There is, therefore, little incentive for companies to conduct clinical studies into its efficacy or to ensure appropriate standardisation of the product. Such standardisation is needed and further studies are required to confirm the efficacy of kava. If this is done then kava may move from the realms of an 'alternative' herbal medicine to becoming accepted as a conventional anxiolytic agent.

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Inpharmae 12 Dec 1998 No. 1167 1173-832419811167-000121$01.00" Adlelntematlonal Limited 1998. All rights ~