Safety, tolerability, and efficacy of quetiapine in youth with schizophrenia or bipolar I disorder: a 26-week, open-label, continuation study.

Objective: The purpose of this study was to describe the safety, tolerability, and efficacy of quetiapine monotherapy continued for up to 26-weeks in youth with schizophrenia or bipolar I disorder.

Methods: Medically healthy boys and girls with a baseline Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV-TR) diagnosis of schizophrenia (ages 13-17 years) or a manic episode of bipolar I disorder (ages 10-17 years) who participated in one of two acute, double-blind, placebo-controlled studies of immediate-release quetiapine were potentially eligible to enroll in a 26-week, open-label study. During the open-label study, quetiapine was flexibly dosed at 400-800 mg/day, with options to reduce dosing to 200 mg/day based on tolerability. Safety and tolerability outcomes assessed from open-label baseline to week 26 included adverse events (AEs), metabolic/laboratory parameters, extrapyramidal symptoms, suicidality, and vital signs.

Results: Of 381 patients enrolled in the open-label study (n=176, schizophrenia; n=205, bipolar disorder diagnosis), 237 patients (62.2%) completed the 26-week study period (71.0%, schizophrenia; 54.6%, bipolar disorder). The most common AEs reported during the study included somnolence, headache, sedation, weight increase, and vomiting. A total of 14.9% of patients experienced a shift to potentially clinically significant low levels of high-density lipoprotein cholesterol and 10.2% of patients experienced a shift to potentially clinically significant high triglyceride levels. Weight gain ≥ 7% was reported in 35.6% of patients between open-label baseline and final visit. After adjustment for normal growth, 18.3% of study participants experienced clinically significant weight gain (i.e., increase in body mass index ≥ 0.5 standard deviations from baseline).

Conclusions: In this 26-week study, quetiapine flexibly dosed at 400-800 mg/day, with options to reduce dosing based on tolerability, was generally safe and well tolerated in youth. Clinicians should monitor lipid profiles and weight gain in youth with schizophrenia or bipolar disorder during treatment with quetiapine.