Comparison of olanzapine-induced weight gain and metabolism abnormalities between topiramate and vitamin C in patients with schizophrenia: a preliminary study

BACKGROUND: Topiramate (TPM) may reduce olanzapine (OLZ)-related weight gain and metabolism abnormalities in patients with schizophrenia. However, differences in the efficacy of OLZ-related weight gain and metabolism abnormalities between TPM and vitamin C (VC) are not clear. This study aimed to investigate whether TPM is more effective than VC in reducing OLZ-induced weight gain and metabolic abnormalities in patients with schizophrenia and explore their patterns. METHODS: This was a 12-week longitudinal comparison study in OLZ-treated patients with schizophrenia. Twenty-two patients who received OLZ monotherapy plus VC treatment (OLZ + VC group) was matched to 22 patients who received OLZ monotherapy plus TPM treatment (OLZ + TPM group). Body mass index (BMI) and metabolism indicators were measured at baseline and 12-weeks follow-up. RESULTS: A significant difference in triglyceride (TG) levels at different time points (pre-treatment: F = 7.89, p = 0.008; 4-weeks treatment: F = 13.19, p = 0.001; 12-weeks treatment: F = 54.48, p < 0.001) was found. Latent profile analysis demonstrated that a 2-class model for OLZ + TPM group (high vs. low BMI in the first 4 weeks) and OLZ + VC group (high vs. low), respectively. CONCLUSION: Our findings suggested that TPM could better mitigates OLZ-induced increase in TG levels. The trajectories of change also differed in all metabolic indexes over time between the two groups.