Paliperidoni

Paliperidoni, in English paliperidone, is an atypical antipsychotic and the principal active metabolite of risperidone. It is used to treat schizophrenia and schizoaffective disorder and is approved in many countries for certain bipolar disorder indications. The drug is available in oral extended-release tablet form and as a long-acting injectable through palmitate esters, marketed for monthly or quarterly dosing.

Mechanism of action centers on antagonism of dopamine D2 and serotonin 5-HT2A receptors, which is characteristic of second-generation antipsychotics. Paliperidone has relatively low affinity for muscarinic, histaminergic, and alpha-adrenergic receptors, contributing to a distinct side-effect profile compared with some other antipsychotics. Its pharmacokinetic properties include limited hepatic metabolism and predominant renal excretion of unchanged drug, which means kidney function strongly influences dosing and drug interactions are typically modest compared with agents heavily processed by the liver.

Common adverse effects include extrapyramidal symptoms such as akathisia, as well as insomnia, somnolence, insomnia, weight changes, and metabolic effects. Hyperprolactinemia, orthostatic hypotension, and gastrointestinal symptoms may occur. As with other antipsychotics, there is a risk of tardive dyskinesia and neuroleptic malignant syndrome, though these are uncommon. Paliperidone carries a boxed warning in many regions regarding increased mortality in elderly patients with dementia-related psychosis. Caution is advised during pregnancy and lactation, and in patients with renal impairment or QT interval prolongation, with dose adjustments and monitoring as appropriate.