Academic journal article Hong Kong Journal of Psychiatry

Risperidone: Truly Non-Cataleptogenic?

Academic journal article Hong Kong Journal of Psychiatry

Risperidone: Truly Non-Cataleptogenic?

Article excerpt

ABSTRACT

Although risperidone has been hailed as a 'truly non-cataleptogenic' antipsychotic and endorsed in standard textbooks as a drug causing minimal or negligible extrapyramidal symptoms at therapeutic doses, our clinical experience with this drug suggests otherwise and prompted this retrospective chart-review of 43 patients receiving risperidone 2-10 mg/day (both median and modal dose: 6 mg/day) for at least 1 month. While taking a mean dose of 5.77 mg/day, which is well within the therapeutic dose range, 29 patients (67%) developed documented extrapyramidal symptoms, mostly parkinsonism but also akathisia and others. Most patients developed extrapyramidal symptoms in the dose range of 5-7 mg/day (17 of 26, 61.5%), although symptoms were also seen in 9 patients receiving a dose of 2-4 mg/day. That the extrapyramidal symptoms were often clinically significant can be gauged from the fact that 83% of those developing extrapyramidal symptoms required institution of an anticholinergic drug, and 31% required a mean risperidone dose reduction of 2 mg/day. Extrapyramidal symptoms had to be managed by risperidone discontinuation (7% of patients) or a combination of an anticholinergic plus risperidone dose reduction (7%). These observations, though of a retrospective and uncontrolled nature, appear too obvious to be ignored and reflect a need for further study into this issue using a prospective, double-blind, randomised, controlled trial.

Key words: Extrapyramidal Symptoms; Retrospective Study; Risperidone; Side Effects

INTRODUCTION

Risperidone, a serotonergic-dopaminergic antagonist, has been hailed as a 'truly non-cataleptogenic' antipsychotic, (1) meaning that it does not produce extrapyramidal symptoms (EPS). The general consensus regarding risperidone is that it certainly causes fewer EPS than other, 'typical' neuroleptics and that any EPS seen in the context of therapeutic dose ranges of risperidone are "usually mild". (2) This view has been broadly endorsed by standard textbooks and research literature alike. (2-9)

In a USA-Canada multicentre project, Marder et al. (3) and Marder and Meibach, (4) reported EPS with risperidone in daily doses of up to 16 mg to be no more common than in the placebo groups. Cunningham suggested no significant difference in EPS reported by patients receiving doses [less than or equal to] 10 mg from the placebo group. (5) Within the recommended therapeutic range (4-8 mg), the incidence and severity of EPS are reported to be much less than 20 mg of haloperidol, even up to 12 months, making risperidone a safer and better tolerated drug than the conventional neuroleptics. Incidence of parkinsonism is reported to be negligible in the therapeutic dose range. (6) Indeed, risperidone has also been shown to decrease pre-existing tremors and rigidity. (1,7) From these observations one would conclude that risperidone has a safe EPS profile. (8,9)

Our day-to-day clinical experience with risperidone, however, suggests otherwise. A sizeable proportion of patients with schizophrenia or other psychotic disorders taking risperidone began to show EPS that were clinically obvious, often necessitating a halt in further dose increases, reduction of dose, or addition of anticholinergic agents such as trihexyphenidyl. This observation prompted us to review the situation by a chart-review study. Thus, this study had the following objectives:

* To ascertain the proportion of patients receiving risperidone who develop EPS.

* To study the characteristics of EPS and their relation to dose and duration of risperidone therapy.

* To determine the clinical significance of EPS in this group as judged by necessity of risperidone dose reduction and/ or anticholinergic supplementation.

* To examine any differences between those patients taking risperidone who developed EPS and those who did not.

MATERIALS AND METHODS

The study was conducted at the Department of Psychiatry, Postgraduate Institute of Medical Education and Research, Chandigarh, India. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.