Risperidone

Risperidone is aan antipsychotic agent which has mixed dopamine D2 receptor and serotonin S2 receptor blocking activities.

• indicated for first onset and acutely relapsed patients
• the blocking of 5HT2 receptors means that it may also selectively relieve negative symptoms - other drugs with the same receptor action have been shown to do this
• has a lower incidence of extra-pyramidal side-effects than conventional anti-psychotics

Note that (1):

• risperidone is not licensed for the treatment of behavioural symptoms of dementia
  • risperidone is not recommended for the treatment of behavioural symptoms of dementia because of an increased risk of cerebrovascular adverse events (including cerebrovascular accidents and transient ischaemic attacks
    • data from randomised clinical trials conducted in the elderly (> 65 years) patients with dementia indicate that there is an approximately 3-fold increased risk of cerebrovascular adverse events (including cerebrovascular accidents and transient ischaemic attacks) with risperidone, compared with placebo. Cerebrovascular adverse events occurred in 3.3% (33/989) of patients treated with risperidone and 1.2% (8/693) of patients treated with placebo. The Odds Ratio was 2.96 (1.33, 7.45 - 95% confidence interval)

Reference:

1. Janssen-Cilag Limited (12th March 2004). The risk of cerebrovascular adverse events in elderly patients with dementia:- important changes to the Summary of Product Characteristics relating to the use of risperidone.
2. Prescribers' Journal (1999); 39 (3): 154-159.