Paliperidon

Paliperidone, often marketed as Invega, is an atypical antipsychotic used to treat schizophrenia and, in some regions, schizoaffective disorder. It is the primary active metabolite of risperidone and exerts its therapeutic effects primarily by antagonizing dopamine D2 and serotonin 5-HT2A receptors in the brain, with additional activity at alpha-1 adrenergic and histamine H1 receptors.

Paliperidone is available as an oral extended-release tablet and as long-acting injectable formulations for maintenance treatment. The oral form is typically dosed once daily and may require adjustment for renal function. The long-acting injectables include paliperidone palmitate, administered monthly or every three months, depending on the product, and are used to improve adherence in adults with schizophrenia.

Pharmacokinetics for paliperidone indicate limited involvement with cytochrome P450 metabolism; it is largely excreted unchanged in urine, so renal impairment requires dose adjustments. This metabolic profile contributes to a relatively lower potential for drug interactions compared with many other antipsychotics.

Safety considerations include common adverse effects such as weight gain, insomnia, and extrapyramidal symptoms like akathisia, though the risk is lower than with many first-generation antipsychotics. Hyperprolactinemia may occur, potentially causing menstrual disturbances or galactorrhea. Paliperidone can prolong the QT interval in susceptible individuals and should be used with caution in those with cardiac conditions or electrolyte disturbances. The use in pregnancy is cautious, and lactation is generally discouraged.

See also: risperidone.