Efficacy of nicergoline in dementia and other age associated forms of cognitive impairment.

BACKGROUND

Nicergoline is an ergot derivative currently in use in over fifty countries for more than three decades, for the treatment of cognitive, affective, and behavioral disorders of older people. It was initially considered as a vasoactive drug and mainly prescribed for cerebrovascular disorders. Recent findings suggest other actions which has provided a rationale for the use of nicergoline for the treatment of various forms of dementia, including Alzheimer's Disease.

OBJECTIVES

To determine whether there is evidence of efficacy of nicergoline in the treatment of dementia and other age-associated forms of cognitive decline,and to assess the safety and tolerability of the drug.

SEARCH STRATEGY

1. Electronic databases search. The Cochrane Controlled Trials Register (which contains citations from the MEDLINE, EMBASE, Psych LIT, and hand searches of geriatric, dementia, psychogeriatric journals, and conference abstracts) was searched using the following terms: 'Nicergoline', 'Sermion'. 2. Reference search. The reference lists of all obtained studies was checked. 3. Pharmaceutical company Pharmacia & Upjohn, owners of the rights to produce and market nicergoline in various different countries, was asked to provide data and reports of clinical trials. In case of unavailability of numerical data in published studies, the authors of each paper, were asked for any published or unpublished data.

SELECTION CRITERIA

• All unconfounded, double-blind, randomized, placebo-controlled, published and unpublished trials were sought. Non-randomized trials were excluded. Open trials were considered for inclusion if patients were randomized to the different treatment groups. - All patients diagnosed as having dementia or other cognitive disorder defined according to classification criteria accepted at the time of each study. - Nicergoline given at any dose for more than one day with placebo control. Type of outcome variables: 1. Cognitive function (as measured by psychometric tests). 2. Clinical impression (such as CIBIC or other clinical global measures of change). 3. Functional performance including dependency. 4. Behavioural disturbance. 5. Safety and acceptability as measured by the incidence of adverse effects (including side-effects) leading to withdrawal. 6. Death 7. Effect on carer 8. Use of services 9. Quality of life.

DATA COLLECTION AND ANALYSIS

A comprehensive search of the international literature and the producing company archives has been performed to identify all possible sources of data for this review. Only those trials fulfilling the inclusion criteria of belonging to either category A or B of allocation concealment, as defined by the Cochrane Organisation, were examined for data extraction by one reviewer. If there was doubt then the other reviewer was consulted. Data availability restricted analyses to 'completers' analyses for the outcome measures. Outcomes able to be assessed included: Behaviour, Cognition, Clinical Judgment, Tolerability, EEG.

MAIN RESULTS

The Sandoz Clinical Assessment Geriatric Scale (SCAG) was the outcome used in the largest number of patients (814 patients). The results from these studies were homogeneous in nature despite including patients observed for periods of time ranging from 2 months to 12 months. There was a difference in favour of the active treatment in reducing the behavioural symptoms described by this scale, -5.18 points [-8.03, -2.33]. This scale has a maximum of 133 points. The therapeutic effects of nicergoline seem to be evident by 2 months of treatment and maintained for 6 months. In general other behavioural outcome measures which include the GRS, the IADL, and the MACC and were episodically used in few studies, failed to demonstrate statistically significant results although there was a trend favouring treatment. Cognitive assessment has been performed in a moderate number of patients with the MMSE (261 patients) and the ADAS-Cog (342 patients). No significant heterogeneity was found for these trials, despite the trials extending over periods of treatment of 3 to 12 months. There was a difference between treatment and control groups on the MMSE favouring nicergoline treatment. At 12 months the effect size was 2.86 [0.98, 4.74] The effect size for the ADAS-Cog, used exclusively with Alzheimer's disease patients, did not reveal a significant benefit. At 12 months the trend favoured treatment (-1.64 [-4.62, 1.34]). The other results from various cognitive measures tended to favour nicergoline but this was based on a small number of cases. The clinical impression of change obtained from a total of 921 patients was homogeneous across the studies, despite reflecting changes over periods of time ranging from 2 to 12 months. The Peto odd ratio for improvement in the subjects treated with nicergoline over these varying time periods was 3.33 [2.50, 4.43]. Tolerability assessed in 1427 patients was homogeneous across all studies and demonstrated a mildly increased risk of adverse events on treatment, OR 1.51[1.10, 2.07].

REVIEWER'S CONCLUSIONS: The clinical studies on nicergoline were carried out with diverse criteria and modalities of evaluation. Despite this, the 14 studies included in this review, have presented generally consistent results. Results of this meta-analysis provide some evidence of positive effects of nicergoline on cognition and behaviour and these effects are supported by an effect on clinical global impression. There was some evidence that there were increased risk of adverse effects associated with nicergoline. These results were obtained on older patients with mild to moderate cognitive and behavioural impairment of various clinical origins, including chronic cerebrovascular disorders and Alzheimer's dementia. The few studies specifically performed on patients with Alzheimer's disease were performed with too few people to give a definitive answer to the questions concerning the use of nicergoline for this form of dementia. This drug has not been evaluated using current diagnostic categories such as MCI or in association with therapeutic agents of different nature such as cholinesterase or antioxidant drugs.