No evidence from randomised controlled trials for or against the use of Zhiling concoction in the treatment of people with vascular dementia

Zhiling is a decoction of 15 Chinese herbs which is thought to contribute to dilating cerebral vessels and increasing cerebral blood flow, as well as reducing serum cholesterol. No randomised controlled trials of Zhiling decoction versus placebo were found and thus its efficacy and safety could not be analysed in this review. There is a need for randomised placebo controlled trials of Zhiling decoction.

Authors' conclusions: 

The currently available evidence is insufficient to assess the potential for Zhiling decoction in the treatment of vascular dementia. The little objective data concerning the management of Zhiling decoction versus Naofukang suggests that Zhiling decoction may be effective in treating vascular dementia.

There is no evidence for or against Zhiling as a treatment for vascular dementia. Further randomised, double-blind, placebo-controlled trials are urgently needed in order to define the relative efficacy and acceptability of Zhiling in vascular dementia.

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Background: 

Zhiling decoction has a fixed composition of 15 Chinese herbs. The properties of each of these herbs and in combination provide the therapeutic rationale for a possible action of Zhiling decoction in dilating cerebral vessels and increasing cerebral blood flow, as well as reducing serum cholesterol. Thus the aim of this review is to evaluate efficacy and safety of Zhiling decoction for the treatment of vascular dementia.

Objectives: 

To assess the efficacy and safety of Zhiling decoction for vascular dementia.

Search strategy: 

The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and LILACS were searched on 17 March 2008 using the term: zhiling. The CDCIG Specialized Register contains records from all major health care databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many trials databases and grey literature sources.

Selection criteria: 

Randomised trials comparing Zhiling decoction with placebo in people with vascular dementia.

Data collection and analysis: 

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials where possible.

Main results: 

In the absence of any suitable randomised placebo-controlled trials in this area, we were unable to perform a meta-analysis.