Systematic Review and Meta-analysis of Anticholinergic Side Effects of Long-acting Antipsychotics

Background: There are few studies on the anticholinergic side effects of long-acting antipsychotics. They tend to be used with stigmatized, severely ill and non-concordant patients rather than first episode psychosis. Aim: To investigate prevalence/incidence rate of anticholinergic side effects of long-acting antipsychotics. Methods: We included all participants with schizophrenia, schizoaffective disorder or schizotypal disorder on depot antipsychotics in the trials within all Cochrane reviews published by the Cochrane schizophrenia group. A search was undertaken in the Cochrane Database and data extracted into Microsoft Excel to analyze frequencies, prevalence and confidence intervals of the anticholinergic side effects of all identified long-acting antipsychotic medications. Result: We found seven reviews for seven depot antipsychotics. For example for fluphenazine decanoate at least a quarter of the participants experienced blurred vision 24.5% (CI 11 to 47) in the short-term, 16 % (CI 10-27) in the medium-term, and 21.4 % (CI 16-28) in the long-term. Conclusion: The anticholinergic side effects of long-acting depot antipsychotics are not any more frequent than the anticholinergic side effects of oral antipsychotics. There is no evidence to suggest that oral medications are better tolerated than long-acting depot preparations.