Systematic Overview of Cochrane Reviews for Anticholinergic Effects of Antipsychotic Drugs

Background: Despite much being written on the topic, there are few surveys investigating the prevalence of anticholinergic adverse effects of antipsychotic drugs. One study, however, used trial-derived data to calculate estimates. Objectives: To investigate the prevalence/incidence rates of anticholinergic effects as viewed from within relevant randomized trials. Methods: Data were extracted from each relevant study included in Cochrane reviews. Data were checked, extracted, and simple frequencies, and 95% confidence intervals (CIs) were calculated. Results: Many trials in relevant reviews reported no data on anticholinergic effects (estimate 40,000 participants). However, data were extracted from 177 studies within 54 reviews (N = 27,328 participants). Most data are short-term (<12 weeks). For blurred vision, the newer generations of drugs have rates of between 10% and 20% (eg, risperidone, n = 1460, 6 randomized controlled trials [RCTs], 11.9% prevalence; CI 10-14; olanzapine, n = 1584; 4 RCTs, 12.2% prevalence; CI 11-14). These estimates are similar to those of sulpiride (n = 186; 2 RCTs, 12.4%; CI 8-18) and chlorpromazine (n = 294; 10 RCTs, 11.2%; CI 8-15), less than trifluoperazine (n = 167; 8 RCTs, 31.1%; CI 25-39), but considerably more than perphenazine (n = 410; 8 RCTs, 3.7%; CI 2-6). Data are presented on a range of anticholinergic effects across different periods. Conclusions: Anticholinergic symptoms are common adverse effects associated with the use of all antipsychotic drugs, and newer-generation drugs are not clearly distinguishable from many older compounds. Adverse effect data should be more accessible.