The impact of adjunctive aripiprazole on olanzapine‐induced metabolic adverse effects in patients with schizophrenia: a systematic review

Background: Olanzapine is a second‐generation atypical antipsychotic drug which is commonly used in the treatment of schizophrenia. It has been associated with metabolic adverse effects such as weight gain, hyperglycaemia, dyslipidaemia, and this has been shown to contribute to the reduction of life expectancy of patients with schizophrenia. This systematic review aimed to assess whether adjunctive aripiprazole is effective at reducing metabolic adverse effects caused by olanzapine. Methods: A systematic review was conducted for this study. A systematic search strategy was developed, recorded, and applied to multiple databases. The literature search found a total of 853 results with the final inclusion of 7 research articles. Based on specific inclusion and exclusion criteria, a wide range of study designs were included in the review, such as randomized control trials (RCTs), open label trials, and case series. Key outcomes were identified, which included glucose levels, lipid profile, body weight, BMI, and waist circumference. The results were recorded and analyzed using narrative synthesis. Results: Statistically significant decreases in fasting triglycerides were consistent across multiple studies. Adjunctive aripiprazole shows potential weight loss benefits, with some studies reporting significant reductions in weight and BMI. Effects on cholesterol and fasting glucose showed reductions, and others showed minimal or no impact. Psychiatric symptom control remained stable in most studies, suggesting that aripiprazole does not negatively affect schizophrenia symptoms while potentially providing metabolic advantages. Conclusion: Adjunctive aripiprazole had variable effects on metabolic parameters in patients on olanzapine therapy; however, reductions in triglycerides appeared consistent among most of the data, and some studies reported significant weight loss. This highlighted that aripiprazole does have some effect in reducing metabolic adverse effects caused by olanzapine.