Pimavanserin is a drug that works by blocking serotonin 5HT2A receptors, and doesn’t interact with the dopamine receptors. It is a licensed drug used to treat hallucinations and delusions in people with Parkinson’s disease psychosis.

A new study published in the New England Journal of Medicine summarizes about a clinical trial conducted in 392 people with psychosis associated to Alzheimer’s disease, Parkinson’s disease, Lewy body, frontotemporal, or vascular dementia.

All participants were given pimavanserin for 12 weeks. Those who met a threshold of symptom improvement were then assigned to pimavanserin or placebo for next 26 weeks.

The trial was stopped early for positive efficacy results. Of the 351 participants, 217 (61.8%) had a sustained initial treatment benefit, of whom 112 were assigned to placebo and 105 to pimavanserin.

Relapse occurred in 28/99 (28.3%) of the placebo group, compared to 12/95 (12.6%) of the pimvanserin group, with pimvanserin more than halving the relapse rate and significantly improving the sustained benefit.

Professor Clive Ballard, Executive Dean of the University of Exeter Medical School, said: “Psychosis affects up to half of all people with dementia, and it’s a particularly distressing symptom – yet there’s currently no safe and effective treatment. Currently used antipsychotics are known to cause harms, and best practice guidelines recommend prescribing for no longer than 12 weeks for people with dementia as a result”.

The results show that relapse rate in the pimavanserin group is lower than the placebo group, indicating that the treatment benefits may be sustained over time. Longer and larger scale trials in the future can explore this further.

They also discovered headache, urinary tract infection and constipation occurred more frequently in the pimavanserin group, but there is no increase in mortality or the other serious events, such as stroke, which are known to increase with other antipsychotics.

Source: Medindia