Paliperidone LAI and Aripiprazole LAI Plasma Level Monitoring in the Prophylaxis of Bipolar Disorder Type I with Manic Predominance

Introduction The objective of this study was the evaluation of utility of plasma level monitoring in the clinical stabilizing efficacy and tolerability of paliperidone palmitate (PP) vs. aripiprazole monohydrate (AM) in bipolar disorder I (BD I) with manic predominance. Methods Fifty-six outpatients of both sexes, age ranging from 18 to 65 years, affected by BD I with manic predominance, orally treated and stabilized after acute episode for at least 2 weeks with paliperidone or aripiprazole (n=31, paliperidone; n=25, aripiprazole) underwent a prospective observational study of switching to the corresponding long-acting injection (LAI) on the basis of clinical evaluation. The efficacy and tolerability of the 2 treatments were assessed by BPRS, PANSS, HAMD21, and MRS rating scales and a check list every month for 12 months. Drug plasma levels determinations (PLs) were performed at the same times. Results A good clinical stability and tolerability of both drugs were reported. Lower mean PLs of PP showed a positive effect on depressive symptoms. AM PLs variability was associated with greater instability of manic symptoms whereas intermediate PLs seem to have more influence on depressive symptomatology. Discussion PLs drug monitoring has been proven to be useful, and further investigations to identify optimal therapeutic ranges for LAI formulations are needed.