Second-generation antipsychotic drug use in hospital inpatients with dementia: the impact of a safety warning on rates of prescribing.

Background: Behavioural and psychological symptoms of dementia are distressing for patients and are frequently treated with second-generation antipsychotics. Concerns about the drugs' safety resulted in a Medicines and Healthcare Products Regulatory Agency (MHRA) warning against their use in March 2009.

Methods: Second-generation antipsychotic drug use was determined amongst patients with dementia admitted to the University Hospitals Birmingham National Health Service Foundation Trust, between July 2005 and December 2011. An interrupted time series analysis was carried out to investigate changes in rates of prescribing following the safety warning. Risperidone was analysed separately, in accordance with its limited licence for use in older adults with dementia, granted in October 2008.

Results: Before the safety warning, second-generation antipsychotic use was increasing in patients with dementia. After the MHRA warning, their use fell by 1.9% per month compared with that before. Use of risperidone continued to rise over the same period, often against the terms of its licence.

Conclusions: Drug safety warnings may influence prescribing practice, although continued use of antipsychotics in dementia could reflect a lack of alternative treatment options.