Evidence for the efficacy of piracetam for dementia or cognitive impairment is inadequate for clinical use but sufficient to justify further research

Flicker L, Grimley Evans J

Published Online:

July 16, 2008

Piracetam was one of the first drugs used for dementia and comes from the class of drugs called nootropics, whose putative actions are still poorly defined. Most of the trials of piracetam were undertaken many years ago and did not use methods which would be currently considered standard. Some of the studies suggested there may be some benefit from piracetam but overall the evidence is not consistent or positive enough to support its use for dementia or cognitive impairment.

Abstract (click to read)

Background:

Piracetam is a drug that may enhance memory and other intellectual functions, but its usefulness in treating dementia is uncertain. It is, however, commonly prescribed for cognitive impairment and dementia in several countries of continental Europe.

Objectives:

To determine the clinical efficacy of piracetam for features of dementia (classified into the major subtypes: vascular, Alzheimer's disease or mixed vascular and Alzheimer's disease, or unclassified dementia) or cognitive impairment not fulfilling diagnostic criteria for 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 December 2007 using the terms piracetam, nootropic and 2-Oxo-1-pyrrolidine. A review by employees and consultants of the manufacturing company, UCB Pharma (Waegemans 2002) included data from unpublished studies not made available to Cochrane reviewers.

Selection criteria:

All unconfounded, randomized, double-blind in which treatment with piracetam was administered for more than a day and compared with placebo in people with dementia of Alzheimer type, vascular dementia, or mixed vascular and Alzheimer's disease, or unclassified dementia, or cognitive impairment not fulfilling diagnostic criteria for dementia.

Data collection and analysis:

Two reviewers independently extracted data from studies fulfilling inclusion criteria. Intention-to-treat analysis was used where feasible and studies were pooled if appropriate. Sensitivity analyses were to be performed to determine if studies performing poorly on quality criteria affected results. The pharmaceutical company marketing piracetam did not release the results of several unpublished trials.

Main results:

Many studies were of cross-over design and first-phase data were unavailable, or could not be extracted. Global Impression of Change (GIC) was the only outcome for which pooling of data was possible, involving only four studies. There was evidence of heterogeneity in the results, chi-square test = 19.17 (df = 3, P < 0.001). The OR for improvement in the piracetam group compared with placebo was 3.43 (95% CI 2.32 to 5.07). Using a fixed-effects model the OR for improvement with piracetam compared with placebo was 3.55 (95% CI 2.45 to 5.16). This estimate was derived from completers rather than from an intention-to-treat analysis as relevant data could not be extracted from the reports.

In the limited data available no significant differences were found between treatment and placebo groups for cognition (immediate memory, visuospatial, MMSE, delayed memory or speech) for dependency, or for depression.

The large volume of unpublished and untraceable data not available to the reviewers raises the possibility of publication bias.

Authors' conclusions:

Published evidence does not support the use of piracetam in the treatment of people with dementia or cognitive impairment. Although effects were found on global impression of change, no benefit was shown by any of the more specific measures of cognitive function.

The evidence indicates a need for further evaluation of piracetam.

This record should be cited as:

Flicker L, Grimley Evans J. Piracetam for dementia or cognitive impairment. Cochrane Database of Systematic Reviews 2001, Issue 2. Art. No.: CD001011. DOI: 10.1002/14651858.CD001011

Assessed as up to date:

April 14, 2008

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Primary Review Group:

Dementia and Cognitive Improvement Group

Health topics:

Mental health > Dementia & cognition > Interventions aimed at interrupting disease processes

Mental health > Dementia & cognition > Prevention: cognitively impaired

Neurology > Dementia & cognition > Interventions aimed at interrupting disease processes

Neurology > Dementia & cognition > Prevention: cognitively impaired

Cochrane Summaries^beta

Independent high-quality evidence for health care decision making

Evidence for the efficacy of piracetam for dementia or cognitive impairment is inadequate for clinical use but sufficient to justify further research

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