Paliperidone

Paliperidone, sold under the brand name Invega among others, is an atypical antipsychotic. It is marketed by Janssen Pharmaceutica. Invega is an extended release formulation of paliperidone that uses the OROS extended release system to allow for once-daily dosing. Paliperidone is mainly used to treat schizophrenia and schizoaffective disorder. Paliperidone, sold under the brand name Invega among others, is an atypical antipsychotic. It is marketed by Janssen Pharmaceutica. Invega is an extended release formulation of paliperidone that uses the OROS extended release system to allow for once-daily dosing. Paliperidone is mainly used to treat schizophrenia and schizoaffective disorder. Paliperidone palmitate is a long-acting injectable formulation of paliperidone palmitoyl ester indicated for once-every 28 days injection after an initial titration period. It is used for the treatment of schizophrenia and schizoaffective disorder. In a 2013 study in a comparison of 15 antipsychotic drugs in effectiveness in treating schizophrenic symptoms, paliperidone was ranked fifth and demonstrated standard-high effectiveness. 10-14% more effective than haloperidol, quetiapine, and aripiprazole, 11% less effective than risperidone (4th), and 43% less effective than clozapine (1st). Sources: The British National Formulary recommends a gradual withdrawal when discontinuing antipsychotics to avoid acute withdrawal syndrome or rapid relapse. Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite. Other symptoms may include restlessness, increased sweating, and trouble sleeping. Less commonly there may be a feeling of the world spinning, numbness, or muscle pains. Symptoms generally resolve after a short period of time. There is tentative evidence that discontinuation of antipsychotics can result in psychosis. It may also result in reoccurrence of the condition that is being treated. Rarely tardive dyskinesia can occur when the medication is stopped. In April 2014, it was reported that 21 Japanese people who had received shots of the long-acting injectable paliperidone to date had died, out of 10,700 individuals prescribed the drug. Paliperidone is the primary active metabolite of the older antipsychotic risperidone. While its specific mechanism of action is unknown, it is believed paliperidone and risperidone act via similar, if not identical, pathways. Its efficacy is believed to result from central dopaminergic and serotonergic antagonism. Food is known to increase the absorption of Invega type ER OROS prolonged-release tablets. Food increased exposure of paliperidone by up to 50-60%, however, half-life was not significantly affected. The effect was probably due to a delay in the transit of the ER OROS formulation in the upper part of the GI channel, resulting in increased absorption. The half-life is 23 hours.