Core pharmacology

Class Group

Second Generation Antipsychotics/Atypical (D2-Antagonism/5-HT2a)

Legacy Cicm Level

-

Introduction

Risperidone is an atypical antipsychotic with limited antimuscarinic effects

Indications Uses

- Psychosis
- Delerium
- Mania
- Agitation
- Behavioural disturbances of dementia

Presentation

Tablets, orally dissolving tablets, oral solution, Depot (2 weekly)

Mechanism of action

D2<5-HT2a, no anticholinergic effects

Physiological effects

CVS: Postural hypotension. QTc

CNS: Obtundation. Risk in parkinson’s or lewy-body dementia. NMS

GIT. Weight gain. Antiemetic

Metabolic/Other. Leukopenia, neutropenia and agranulocytosis have been reported

Absorption

66% oral biovailability

Protein binding

Highly protein bound

Metabolism

CYP2D6 converts risperidone to paliperidone (active)

Half-life

Elimination T1/2 of 3-20 hours, paliperidone T1/2 is 24 hours