A comparison of extrapyramidal symptoms in older outpatients treated with quetiapine or risperidone

To compare the tolerability of quetiapine with risperidone in older outpatients.

Post hoc analysis of a subset of older patients (aged 60-80; n = 92) from a randomized, 4-month, multicenter, open-label trial comparing quetiapine and risperidone in an outpatient setting. Participants had various neuropsychiatric disorders associated with psychosis as defined by criteria from the Diagnostic and Statistical Manual of Mental Disorders (4th edn).

The main outcome measure was an extrapyramidal symptoms (EPS) checklist, used to assess motor symptoms, including parkinsonism, at baseline and after treatment. The Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression scale were used to assess therapeutic efficacy.

Substantial EPS (defined as EPS requiring a dosage adjustment or use of medication to reduce EPS) occurred less often with quetiapine (median dosage, 200 mg/day) than with risperidone (median dosage, 3 mg/day); odds ratio, 0.31 (P < 0.03). Quetiapine was also less likely than risperidone to cause akathisia or hypertonia. Both compounds produced comparable reductions in PANSS scores.

Interpretation of findings in this report is limited by the open-label design of the study and the post hoc nature of this analysis. However, the results suggest that quetiapine, when given within the recommended dosage range, has a benign EPS profile, with potentially greater tolerability and comparable efficacy to risperidone in older outpatients with psychotic disorders.