BACKGROUND

CDP-choline has a widespread, but not exclusive use in the treatment of disorders of a cerebrovascular nature. The many years of its use have caused an evolution in dosage, method of administration, and selection of patients to which the treatment was given. Design of the clinical studies, including length of observation, severity of disease, and methodology of evaluation of the results have also varied. In spite of uncertainties about its efficacy, CDP-choline is frequently prescribed for cognitive impairment in several continental European countries, especially when the clinical picture is predominantly one of cerebrovascular disease.

OBJECTIVES

The objective is to assess the efficacy of CDP-choline (cytidinediphosphocholine) in the treatment of cognitive, emotional, and behavioural deficits associated with chronic cerebral disorders of older people.

SEARCH STRATEGY

The CDCIG register of trials and other databases were searched in July 2000 for all relevant, non-animal randomized controlled trials using the terms CDP-choline/CDP, Citicoline, Cytidine Diphosphate choline and Diphosphocholine. The Psychlit (1974-1996), Psychiatry (1980-1996) and MEDLINE electronic databases have been searched independently by the reviewers. The reviewers have also contacted manufacturers of CDP-choline.

SELECTION CRITERIA

All relevant, non-animal, unconfounded, double-blind, placebo-controlled, randomized trials of CDP-choline for patients with cognitive impairment due to chronic cerebral disorders are considered for inclusion in the review.

DATA COLLECTION AND ANALYSIS

Two reviewers independently reviewed the included studies, extracted the data, and pooled when appropriate and possible. The pooled odd ratios (95% CI) or the average differences (95% CI) were estimated. No intention-to-treat data were available from the studies included.

MAIN RESULTS

Seven of the included studies observed the subjects for a period between 20 to 30 days, one study was of 6 weeks duration, 3 studies used cycles extending over 2 and 3 months and one study observed continuous administration over 3 months. The studies differed in dose, inclusion criteria for subjects, and outcome measures. Results are reported for the domains of attention, memory testing, behavioural rating scales, global clinical impression and tolerability. There is no significant evidence of a beneficial effect of CDP-choline on attention. There are modest, but statistically significant, beneficial effects of CDP-choline on memory function and behaviour. For the outcome of clinical global impression, the odds ratio for improvement in the subjects treated with CDP-choline as opposed to the subjects treated with placebo is 8.89 [5.19 to 15.22]. The drug is well tolerated.

REVIEWER'S CONCLUSIONS: There is some evidence that CDP-choline has a positive effect on memory and behaviour in at least the short term. The evidence of benefit from global impression is stronger, but is still limited by the duration of the studies. There is evidence that the effect of treatment is more homogeneous for patients with cognitive impairment secondary to cerebrovascular disorder. Further studies with a more appropriate length of treatment are recommended owing to the chronic and irreversible nature of the disorders for which this treatment is indicated.