Lower Risk for Body Weight Gain and Better Control of Appetite After Switching Risperidone to Paliperidone in a Schizoaffective Patient

To the Editor: Paliperidone, a metabolite of risperidone, can also treat schizoaffective disorder. Its characteristics in metabolic profile remain controversial in recent years.^1,2 However, I want to present a schizoaffective patient with a lower risk for body weight gain and a better control of appetite after switching from risperidone to paliperidone.

Case Report

Miss C, a 43-year-old woman with schizoaffective disorder, received risperidone 5 mg/day and duloxetine 60 mg/day for 2 to 3 years. She had significant improvements of psychotic symptoms and depression symptoms [Brief Psychiatric Rating Scale-18 (BPRS-18) scores: 13 and Hamilton Rating Scales for Depression-17 (HDRS-17) scores: 8]. She also had a stable job in the environmental protection agency of the government. However, she had progressive body weight gain problems associated with increased appetite since the use of risperidone and duloxetine [body mass index (BMI): 29.58‒31.79; body weight: 84‒99 kg within 2 years]. She started to worry a lot about persistent body weight gain and related metabolic syndrome. After careful consideration about the balance between the worsening of psychotic symptoms and persistent body weight gain problems, the risperidone 5 mg/day was switched to paliperidone 9 mg/day. We still continued duloxetine 60 mg/day in her treatment regimen. After a 2-month paliperidone treatment, her psychotic symptoms remained stable (BPRS-18 score: 12 and HDRS-17 score: 7), and her appetite started to decline with a decrease in body weight (BMI scores 30.75; body weight: 91.5 kg). No significant side effects after the switch of the antipsychotics were observed. She felt more satisfied with the improvement in quality of life, clear thinking, and less inattention after switching to paliperidone.

Discussion

In this case, risperidone is related to significant body weight gain and increased appetite. The switch to paliperidone can lead to less body weight gain without significant exacerbation of psychotic symptoms. Nasrallah et al. suggested that the dopamine D2 receptor and serotonin receptor affinity might be related to body weight side effects of risperidone.³ The review of oral paliperidone showed that paliperidone might decrease cholesterol and low density lipoprotein.¹ However, Nussbaum and Stroup found that paliperidone might cause body weight gain.² In a head-to-head study, paliperidone showed superiority over olanzapine in the metabolic side effect profile, insulin resistance, elevated triglyceride, and weight gain.⁴ Meltzer et al. reported that paliperidone even can show no significant differences of in weight gain, glucose handling, and lipid metabolism compared with the placebo group.⁵ In a 30-week trial, paliperidone showed no significant weight gain and relatively safe profile.⁶ However, the results of several studies were against the lower weight gain result of paliperidone.^7–9 Kim et al. suggested that paliperidone-related weight gain might only occur in one out of four patients who received paliperidone treatment.¹⁰ Kim et al.’s study might provide an optimal solution for paliperidone-related weight gain. This case might belong to another group with no significant weight gain under paliperidone treatment. The switch management might provide us with a treatment choice when facing risperidone-related significant weight gain and fear of exacerbations of psychotic symptoms while switch to another kind of atypical antipsychotic.