Objectives: To describe a cohort of young users of risperidone and quetiapine in the province of Manitoba (Canada) and assess the risk for movement disorders in the two treatments.
Methods: This was a population-based study conducted on all residents of the province of 19 years of age and younger who received prescriptions for risperidone or quetiapine between April 1, 1996, and March 31, 2011. Incident rates of antipsychotic use were reported. The risk for movement disorders in patients treated with quetiapine compared with those treated with risperidone was assessed by time-to-event analysis using Cox proportional hazards models.
Results: Between April 1, 1996, and March 31, 2011, 23,888 youth (age ≤19 years) were prescribed an antipsychotic agent. Among them, 8756 were identified as new incident users. After applying exclusion criteria, 2594 individuals comprised the cohort of users of risperidone and quetiapine. The use of quetiapine was associated with a lower risk of extrapyramidal symptoms (EPSs) adverse events. The unadjusted and adjusted hazard ratios (95% confidence interval [CI]) for quetiapine versus risperidone were 0.83 (0.56-1.25) and 0.53 (0.34-0.83), respectively.
Conclusion: EPS diagnoses have been detected in children treated with quetiapine; however, the risk of movement disorders appears to be higher with treatment with risperidone. Clinicians should always take into consideration the risk-benefit before treating children with antipsychotic medications and should be vigilant of the onset of drug-induced adverse events.
Keywords: antipsychotics; movement disorders; quetiapine; risperidone.