Abstract
Objective: To investigate the admission rates, drug attitudes, and psychiatric symptoms after changing to oral antipsychotics from once-monthly paliperidone palmitate in schizophrenia.
Methodology: The retrospective study included 105 patients with schizophrenia and were divided to those who continued use of paliperidone palmitate once-monthly (maintenance group) and those who changed to oral antipsychotics (change group). The change group was further divided into an adherent and a non-adherent group based on a cutoff score of 4 on the Drug Attitude Inventory. Admission rates and Positive and Negative Syndrome Scale and 10-item Drug Attitude Inventory scores were collected. Generalized estimating equation analysis and two-way repeated-measures analysis of variance were used for the analyses.
Results: With changing to oral antipsychotics from once-monthly dose, the admission rate significantly decreased during successive periods. The scores of the 10-item Drug Attitude Inventory increased and those of the Positive and Negative Syndrome Scale decreased across the three assessment periods, but the effect of group was non-significant. These improvements were halted by changing to oral antipsychotics. The Drug Attitude Inventory and Positive and Negative Syndrome Scale scores did not change before and after changing to oral antipsychotics in the adherent and non-adherent subgroups of the change group.
Conclusion: Paliperidone palmitate once-monthly use could effectively decrease the admission rates, improve psychiatric symptoms, and positively change drug attitudes in schizophrenia during a short period of 6 months.

Key words: Schizophrenia, drug attitude, psychiatric symptoms, oral antipsychotics, paliperidone palmitate once-monthly.