Anticholinergic Burden in Schizophrenia
Anticholinergic antiparkinsonian agents often cause side-effects including cognitive impairment, dry mouth, and constipation while they diminish antipsychotic-induced parkinsonian symptoms. The introduction of second generation antipsychotics (SGA) brought fewer neurological side effects. However, anticholinergic coprescription rates are still as high as 12-65% in patients on SGA that are much higher than the incidence of EPS reported in clinical trials (3-20%). This apparently discrepancy is likely explained, in part, by the established tradition of routine use of this medications. Older patients are particularly sensitive to anticholinergic side-effects due to age-related changes in pharmacokinetics and pharmacodynamics. In this study, we will examine the safety and benefits of reducing the dose of a frequently prescribed anticholinergics, benztropine, on cognitive function, extrapyramidal symptoms, and psychotic symptoms in older subjects with a primary psychotic disorder.
|Study Design:||Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Anticholinergic Burden in Schizophrenia|
- percentage of participants who successfully withdraw from anticholinergic antiparkinsonian agents. [ Time Frame: at the end of the study ] [ Designated as safety issue: No ]
- effect of reducing the dose of benztropine on EPS and anticholinergic side-effects including cognitive impairments. [ Time Frame: intermittent ] [ Designated as safety issue: No ]
|Study Start Date:||June 2007|
|Primary Completion Date:||December 2011 (Final data collection date for primary outcome measure)|
Patients aged ≥ 50 years suffering from a primary psychotic disorder treated with a SGA and benztropine concomittantly at any dose steadily for at least 3 months will be eligible to participate in this study. The dose of benztropine will be reduced by 0.5mg per week. During this 8-week study period, extrapyramidal symptoms will be assessed on a weekly basis. The clinical assessments will be repeated 8 weeks after the initial assessments.
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|Centre for Addiction and Mental Health|
|Toronto, Ontario, Canada, M5T 1R8|
|Principal Investigator:||Ariel Graff, MD||Centre for Addiction and Mental Health|