The long-term effect of quetiapine (Seroquel TM ) monotherapy on weight in patients with schizophrenia

INTRODUCTION: Quetiapine (Seroquel TM ) is an atypical antipsychoticdrug with demonstrated efficacy and tolerability. In particular, placebo-level extrapyramidal symptoms (EPS) across the entire dose range and a low propensity to cause sexual dysfunction suggest it may be associated with greater patient acceptability than alternative treatments. However, other side-effects, such as weight gain, may also have a significant impact on treatment acceptability. METHOD: We report the long-term weight changes observed in a cohort of 427 patients with schizophrenia from controlled and open-label extension (OLE) trials, in which quetiapine (mean dose 475 mg/day after 1 year) was the only antipsychotic medication during the OLE period. RESULTS: In these patients, there was no overall effect on weight across the body mass index (BMI) spectrum. There were no dose-related effects on weight, and only one patient withdrew from treatment due to an adverse event of weight gain. Quetiapine appeared to have a weightneutral or 'normalizing' effect, with a tendency towards favourable shifts in bodyweight in underweight patients (BMI<18.5 kg/m 2 ) and severely obese patients (BMI>35 kg/m 2 ). CONCLUSION: These results indicate that long-term weight changes with quetiapine monotherapy are minimal and potentially beneficial, and do not appear to raise the medical concerns associated with some other atypical agents.