Tolerability of extended‐release quetiapine fumarate compared with immediate‐release quetiapine fumarate in older patients with Alzheimer's disease with symptoms of psychosis and/or agitation: a randomised, double‐blind, parallel‐group study

Abstract

The objective of this study was to assess the safety and tolerability of extended-release quetiapine fumarate (quetiapine XR) compared with quetiapine immediate-release (quetiapine IR) in older patients with Alzheimer's disease with symptoms of psychosis and/or agitation. This was a 6-week, double-blind, double-dummy, randomised study. Of the 109 patients screened, 100 were randomised to receive quetiapine XR (n = 68) or quetiapine IR (n = 32), at doses of 50 and 25 mg/day, respectively. Treatment was escalated to 100 mg/day by Day 4. At Day 8, a flexible-dose (50-300 mg/day) period began when dose adjustment was made at the investigator's discretion. The primary variable was incidence and type of adverse events (AEs). Secondary variables included efficacy and other safety assessments. Mean daily doses were 143.6 and 142.0 mg in the quetiapine XR and quetiapine IR groups, respectively. Ninety patients completed the study; only one withdrew (in the quetiapine XR group) because of an AE. Laboratory evaluations identified severe neutropaenia (one patient), mild neutropaenia (three patients) and eosinophilia (five patients); however, these were not reported, as AEs and confounding factors, such as patient age, concomitant illness and medication, made it difficult to determine any relationship to quetiapine treatment. Numerical improvements from baseline were seen across both treatment groups in Neuropsychiatric Inventory frequency × severity total, Neuropsychiatric Inventory-Nursing Home version, Cohen-Mansfield Agitation Inventory, Clinical Global Impression-Severity of Illness and Clinical Global Impression-Improvement scores. Quetiapine XR dosed up to 300 mg/day was generally well tolerated, with a similar profile to that of quetiapine IR.