The safety of quetiapine: results of a post-marketing surveillance study on 1728 patients in England

Abstract

The safety of the atypical antipsychotic quetiapine as used in general practice in England was examined by prescription-event monitoring (PEM). Patients were identified from dispensed National Health Service (NHS) prescriptions issued by general practitioners (GPs) for quetiapine between October 1997 and July 1999. The outcome data were event reports obtained by sending questionnaires ('green forms') to the prescribing doctor at Least 6 months after the first prescription for an individual patient. Green forms with clinically useful information on 1728 patients (median age 39 years (IQR 30-56); 53% female) were received. The most frequently reported event during the first month of treatment was 'drowsiness/sedation' (47; 3% cohort). This was also the most frequently reported specified adverse drug reaction (ADR) to quetiapine (7; 11% of 65 reported ADRs) and the highest reported clinical reason for stopping quetiapine (51; 6% of the 734 reported reasons for stopping). There was a low incidence of extrapyramidal disease (21 during treatment, 1% of cohort) and hyperprolactinaemia (three during treatment, 0.2%) in this study. Three cases of diabetes mellitus in this cohort were reported to be a new diagnosis. Six pregnancies were reported during treatment with quetiapine, five of which were exposed during the first trimester only. There were four Live births with no reported congenital abnormaLities. Fifty-six deaths were reported during this study (3% cohort). The most frequently reported causes of death reLated to the cardiovascular (18) and respiratory (15) systems. The results of this post-marketing surveillance study demonstrated that quetiapine is generally well-tolerated when used in general practice.