Therapeutic drug monitoring of perospirone: The lowest effective plasma concentration in patients with schizophrenia

Objectives: This study investigated the effects of demographic factors such as age, sex and comedications on the plasma concentrations of perospirone in individuals diagnosed with schizophrenia. Additionally, the relationship between these plasma levels and the clinical efficacy of the medication was explored.Methods: Data regarding the plasma concentration of perospirone in patients with schizophrenia were obtained from the Xi'an Mental Health Center and were retrospectively analysed.Results: The study results revealed a range of 0.50-1.59 ng/mL for the 25th-75th percentile of perospirone concentration in the plasma, which ranged from 0.07 to 6.0 ng/mL. The plasma concentration of perospirone increased with the daily oral dose (r = 0.283, P < 0.05). Furthermore, patients with higher plasma perospirone concentrations and concentration-to-dose ratios (C/D) tended to be older or were women. Notably, the coad-ministration of valproate significantly reduced perospirone concentration and the C/D ratio by 54.7% and 35.3%, respectively (P < 0.01). Receiver operating characteristics curve analyses revealed that patients exhibited a good clinical response when their plasma perospirone concentrations were >= 1.17 ng/mL.Conclusion: The findings suggest that therapeutic drug monitoring of perospirone and adjustments to achieve steady-state concentrations of >= 1.17 ng/mL can be beneficial for optimising treatment for patients with schizophrenia.