Objective: Second-generation antipsychotic (SGA) effects in youth were monitored to quantify extrapyramidal side effects (EPS) and to identify risk profiles for treatment-emergent EPS.
Method: Data were analyzed for the nonrandomized, prospective Second-generation Antipsychotic Treatment Indications, Effectiveness and Tolerability in Youth (SATIETY) inception cohort study. EPS were assessed at baseline and 4, 8, and 12 weeks after naturalistic SGA initiation for schizophrenia, mood, disruptive behavior, and autism spectrum disorders using the Simpson-Angus Scale (SAS), Barnes Akathisia Scale, Abnormal Involuntary Movement Scale (AIMS), and Treatment Emergent Side Effect Scale. Drug-induced parkinsonism was defined by incident mean SAS score >0.33, anticholinergic initiation, or increasing total SAS score ≥2 in patients with baseline EPS.
Results: In 342 youth aged 13.6 ± 3.5 years (male = 58.2%, antipsychotic-naive = 65.8%), 15.2% developed drug-induced parkinsonism. Raw SGA-grouped drug-induced parkinsonism rates were as follows: quetiapine = 1.5%, olanzapine = 13.8%, risperidone = 16.1%, ziprasidone = 20.0%, and aripiprazole = 27.3%. SGA type, dose, higher age, and lower baseline functioning were jointly associated with drug-induced parkinsonism (R(2) = 0.18; p < .0001). Controlling for these factors, drug-induced parkinsonism rates were significantly lower only for quetiapine and olanzapine. Subjectively reported EPS (5%), EPS-related treatment discontinuation (3.3%), and anticholinergic initiation (3%) were infrequent. Anticholinergic initiation was most frequent with risperidone (10.2%; p = .0004). Treatment-emergent dyskinesia ranged from 4.5% (aripiprazole) to 15.5% (olanzapine). SGA type, younger age, white race/ethnicity, and baseline AIMS were jointly associated with treatment-emergent dyskinesia (R(2) = 0.31; p < .0001). Controlling for these factors, treatment-emergent dyskinesia rates differed among SGA subgroups, with higher rates with olanzapine and ziprasidone. At baseline, psychostimulant use was associated with dyskinesia, and number of psychotropic comedications was associated with subjective EPS.
Conclusion: In youth, SGA-related EPS rates did not generally exceed those reported in adults, with particularly low rates with quetiapine and olanzapine.
Keywords: dyskinesia; extrapyramidal; parkinsonism; second-generation antipsychotic; youth.
Copyright © 2015 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.