Individuals with schizophrenia are more likely than members of the general population to be overweight or obese⁵. Moreover, a large number of patients with schizophrenia experience clinically important weight increases after starting therapy with an antipsychotic. Weight gain is a concern for patients because it contributes to type 2 diabetes mellitus, dyslipidemia, and hypertension, which increase the risk for cardiovascular events⁶. Excessive weight can also have important effects on adherence to prescribed medication, the ability to participate in rehabilitation efforts⁵, and self-regard. Although factors of daily life such as diet and sedentary lifestyle also contribute to weight problems in patients with schizophrenia, strong evidence implicates antipsychotic medication as a key contributor^5,7. Some antipsychotics are clearly more likely to induce weight gain than others, but no drug is completely free of a weight gain effect and none causes weight gain in every patient⁸. The incidence of clinically significant weight increase (≥7%) associated with atypical antipsychotic treatment has been reported in a range from 8.1% (aripiprazole)⁹ to 22.2% (olanzapine)¹⁰.

Since all antipsychotics, including cariprazine, are associated with weight gain in some patients, weight should be monitored for all individuals with schizophrenia¹. Body mass index (BMI) is considered the most widely recognized standard for determining the need for intervention⁵. The patient’s waist size may also be informative in terms of weight status; women with a waist size of ≥ 90 cm and men with a waist size ≥ 100 cm have increased risks of high blood pressure, type II diabetes, dyslipidemia, and metabolic syndrome¹¹.

Focusing on preventing initial weight gain and obesity is a good strategy for patients with schizophrenia since it’s difficult to lose weight and weight loss interventions aren’t often effective⁵. Patients and their caregivers should be educated about the potential for weight gain and the associated health risks⁵. A family history of obesity or diabetes provides an additional indication that weight gain could be associated with adverse health risks for a particular patient⁵. Patients should also be encouraged to monitor their own weight⁵.

To help patients control weight gain, and weight and BMI should be recorded before medication is started or changed, and at every visit for the first 6 months after medication initiation or change⁵. When the patient’s weight stabilizes, weight and BMI should be monitored every quarter for patients of normal weight and more frequently if the patient is overweight. Patients who are seen at intervals of more than 1 month should be instructed to monitor themselves and to notify their clinician if they begin to gain weight⁵. If weight gain occurs, interventions can include nutritional counselling, exercise programs, the use of weight loss medications, and/or a change of antipsychotic medication to one associated with less weight gain^14,15.

As with all antipsychotics, changes in body weight have been observed with cariprazine treatment¹. When taking all studies of cariprazine in schizophrenia into account, a slight weight increase of 1 kg was observed (short term as well as long term)¹. In the targeted 1.5-6 mg/d dose range, potentially significant weight gain was reported in 9.0% of cariprazine treated patients in the long-term study¹. Moreover 5.1% of patients experienced adverse events related to weight gain in the cariprazine group compared to 1.5% in the placebo group¹⁶. Collectively, these data suggest that cariprazine is on the lower end of the atypical antipsychotic weight gain hierarchy³.

Along with its good weight profile, cariprazine does not appear to have clinically relevant adverse effects on metabolic variables. Mean (SD) changes from baseline in the approved dose range were small and clinically insignificant in most metabolic parameters⁴.

The incidence of patients with adverse events associated with hyperlipidaemia was approximately 1% across all treatment groups. The incidence of patients with adverse events associated with hyperglycemia and diabetes mellitus was < 1% with cariprazine and 1% with placebo¹⁶.

Compared to placebo, in the short term studies, shifts from normal to high levels in lipids and glucose were generally similar for placebo and cariprazine².

Overall, study results indicate that cariprazine could be a good treatment choice for patients with schizophrenia who have weight or metabolic concerns that could complicate comorbid conditions such as cardiovascular disease or diabetes^2-4.