An important determinant of the clinical course in bipolar disorder is adherence or non-adherence to medications, estimated at 10--60 % in these patients even during their euthymic periods. Non adherence to mood stabilizers and antipsychotics in the treatment of bipolar disorder increase the risk of suicide, relapse, and rehospitalization. An alternative to reduce the non-adherence of oral medication is the usage of long acting injectable (LAI) antipsychotic.
The use LAI in patient with bipolar disorder are widely use while the support for their use is rather limited. Second generation antipsychotics (SGAs) are more common compare to first generation antipsychotics (FGAs) in treating bipolar disorder. Study for FGAs long acting injection usage in Bipolar Disorder are scarcely limited to open trials, case series and retrospective analyses. A study conducted with flupenxitol LAI showed neither effect nor superiority over lithium. Haloperidol LAI and fluphenazine LAI increase the risk of depressive episode when the usage of lithium had been stopped before the LAI started.
In a randomized controlled trial by Vieta, et al (2012), risperidone LAI is effective either as a sole treatment or as an adjunct to treat manic, hypomanic and manic-mixed episode but has no effect regarding the depressive episode. Another SGA, Paliperidone LAI has similar effects to risperidone LAI. Oral form of paliperidone is use to prevents manic relapse in bipolar disorder, while the LAI form of paliperidone according to case series by Buoli M,et al (2015) also showed good outcome in preventing manic relapse.3,15 However, there were no controlled studies that compare FGAs and SGAs LAI.
Paliperidone LAI leads to significantly less extrapyramidal symptoms than older generation antipsychotics. Compared to oral SGAs, Paliperidone LAI showed a similar safety profile as oral SGAs, but with greater incidence of mild injection-site pain. A novel 3-monthly formulation of Paliperidone LAI has shown similar safety and efficacy as once-monthly paliperidone LAI compared to placebo. This LAI may be most effective in patients with prior failed treatment of oral antipsychotics or other LAIs.
Paliperidone LAI reduced the number of medication non-compliance, relapse, number of hospital readmission and length of inpatient stay by decreasing the number of manic and mixed episodes, thereby having a positive effects on the course of the disease. Paliperidone LAI as an adjunctive in patients with bipolar disorder are beneficial, save, and could help in improving the prognosis of bipolar disorder.