Augmentation of aripiprazole by flupenthixol decanoate in poorly responsive schizophrenia: a randomized clinical study

OBJECTIVE: According to some studies, while first-generation antipsychotics were associated with slightly better outcomes and lower costs in comparison with second-generation antipsychotics, atypical antipsychotics have become the most commonly used class of antipsychotic drugs in clinical practice. The objective of this study was to examine whether there could be any positive outcome if flupenthixol decanoate was added, as an adjuvant, to aripiprazole in poorly responsive cases of schizophrenia.

METHODS: Twenty-four male inpatients with diagnosis of schizophrenia, according to the DSM5 diagnostic criteria, who had shown poor response to aripiprazole, were entered into an eightweek, parallel group, single-blind study for random assignment to either aripiprazole plus augmentative flupenthixol decanoate or current antipsychotic treatment in a 1:1 ratio. Primary outcome measures of the study were changes in the mean total scores of the Scale for Assessment of Positive Symptoms (SAPS) and the Scale for Assessment of Negative Symptoms (SANS). The secondary measures were the Schedule for Assessment of Insight (SAI), the Clinical Global Impressions-Severity Scale (CGI-S), and the Simpson-Angus Scale (SAS).

RESULTS: According to the findings, the mean total scores of SAPS, SAI, and CGI-S in the augmented group decreased significantly in comparison with the aripiprazole group (p < .01, p < .05, p < .01 , respectively), with around 19.55% decrement of SAPS in the augmented group. Conversely, the reduction in the mean total score of SANS was not significant in between-group analysis (p > .05). Also, the mean total score of SAS was significantly increased in the augmented group (p < .01). The effect-size analysis showed a large improvement with flupenthixol augmentation in terms of SAPS, SAI, and CGI-S scores.

CONCLUSIONS: While emergence of extra-pyramidal side effects should not be overlooked by clinicians, adding flupenthixol decanoate to aripiprazole may be beneficial for some cases of poorly responsive schizophrenia.