Objectives:
To assess daytime cognitive performance, sedation and treatment satisfaction in patients with schizophrenia receiving quetiapine extended release (XR) versus quetiapine immediate release (IR).
Methods:
Phase IV prospective, double-blind, crossover study (NCT01213836). Patients (N=66) with stable schizophrenia, treated with XR or IR before study start, were randomised (1:1) to treatment with XR followed by IR, or IR followed by XR, at the dose received before enrolment (400-750mg). After 10-16days on formulation 1, patients switched to formulation 2. Assessments from three post-dose visits (≥5days following treatment on each formulation) were analysed. Cognitive performance was measured by CogState Cognition testing. Sedation, treatment satisfaction and safety were also assessed.
Results:
65 patients received treatment (69.2% male; mean age 37.8years). Daytime cognitive functioning was similar for both groups; adjusted mean difference in Attentional Composite Score in XR and IR patients was 0.005 (p=0.907). Patients receiving XR were less sedated than those receiving IR, (Bond-Lader visual analogue scale score, mean [SD]: 23.5 [19.0] vs 28.6 [21.4]); estimated overall treatment difference: 5.2 (95% CI: 2.3, 8.2; p<0.0009). Patients receiving XR reported feeling less sedated than those on IR (Stanford Sleepiness Scale, mean [SD]: 2.4 [0.9] vs 2.6 [1.0]); estimated overall treatment difference: 0.28 (95% CI: 0.12, 0.43; p<0.0008). Patients reported improved overall treatment satisfaction (p=0.0417) and milder side effects (p=0.0035) with XR. Safety profile was similar in both groups.
Conclusion:
Daytime cognitive performance was similar for both groups. XR was associated with less daytime sedation and improved patient satisfaction than IR.
