Exposure to antipsychotics and risk of stroke: self controlled case series study

Abstract

Objectives: To investigate the association between use of typical and atypical antipsychotic drugs and incidence of stroke in patients with and without dementia.

Design: Self controlled case series.

Setting: UK based electronic primary care records in the general practice research database (GPRD).

Participants: All patients registered in the database with a recorded incident stroke and at least one prescription for any antipsychotic drug before the end of 2002: 6790 eligible participants were identified and included in the final analysis.

Main outcome measures: Rate ratio for stroke in periods of time exposed to antipsychotics compared with unexposed periods.

Results: Use of any antipsychotic drug was associated with a rate ratio for stroke of 1.73 (95% confidence interval 1.60 to 1.87): 1.69 (1.55 to 1.84) for typical antipsychotics and 2.32 (1.73 to 3.10) for atypical antipsychotics. In patients receiving any antipsychotic drug, the rate ratios were 3.50 (2.97 to 4.12) for those with dementia and 1.41 (1.29 to 1.55) for those without dementia.

Conclusions: All antipsychotics are associated with an increased risk of stroke, and the risk might be higher in patients receiving atypical antipsychotics than those receiving typical antipsychotics. People with dementia seem to be at a higher risk of an associated stroke than people without dementia and use of antipsychotics should, when possible, be avoided in these patients.

Pictorial representation of study design. Figure illustrates single individual prescribed antipsychotic drug during their observation period. All participants included in analysis had at least one prescription for an antipsychotic drug and a single incident stroke. Rate ratios presented are pooled estimates derived from rate of events during risk (exposed) periods divided by rate of events during baseline periods; age is adjusted for at all stages of analysis. Incident stroke can occur during any one of three exposure periods: baseline, exposed, or washout period