Role of metformin in the management of antipsychotic-induced weight gain

Abstract

O besity is a growing public health concern with significant economic burden. In general, someone with a BMI of 25kg/m 2 or over is classed as overweight and with a BMI of 30kg/m 2 or over as obese. A waist circumference of 94cm or over in men and 80cm or over in women carries a high risk for coronary heart disease and the metabolic syndrome. The prevalence of both diabetes and obesity among individuals with schizophrenia and affective disorders is 1.5-2.0 times higher than in the general population. People with mental illness are three times more likely to develop diabetes and twice as likely to die from heart disease. 1 Many characteristics of people with schizophrenia, such as sedentary behaviour, may contribute to the apparently higher prevalence of metabolic abnormalities.With an increasing trend for using atypical antipsychotics (second-generation antipsychotics) over typical antipsychotics (first-generation antipsychotics) for various psychiatric disorders, the adverse effect concern has shifted from extrapyramidal side effects to weight gain and impaired metabolic control. 2 In addition to adversely affecting quality of life and medication adherence, weight gain and metabolic abnormalities are reliable risk factors for premature cardiovascular morbidity and mortality, and diabetes.

Topiramate and Metformin Are Effective Add-On Treatments in Controlling Antipsychotic-Induced Weight Gain: A Systematic Review and Network Meta-Analysis

“…Current published systematic reviews on add-ons controlling APD-induced weight gain were either focused on one particular medication (e.g., metformin) ( Housel et al, 2009 ; Miller, 2009 ; Prajapati, 2014 ; de Silva et al, 2016 ; Siskind et al, 2016 ), or indirectly compared different medications in a qualitative way, i.e., ranking the treatment effects simply based on the pair-wise meta-analyses results ( Miller, 2009 ; Maayan et al, 2010 ; De Hert et al, 2012 ; Kishi et al, 2014 ; Mizuno et al, 2014 ; Choi, 2015 ; Whitney et al, 2015 ; Zimbron et al, 2016 ). The current review aims to quantitatively synthesize the weight and BMI reduction effects through a combination of both direct and indirect evidence.…”

Evaluation of a general practitioner‐led cardiometabolic clinic: Physical health profile and treatment outcomes for clients on clozapine

“…In particular, approximately half of the clients were prescribed metformin. Metformin is the first‐line medication for the treatment of type II diabetes, and is indicated for clients who are prescribed antipsychotic medication and who have or are at risk of metabolic syndrome (Prajapati ; Zheng et al . ).…”

“…To this effect, in Australia, mandatory monitoring protocols are in place for the monitoring of the antipsychotic medication clozapine, as this medication is associated with a particularly high risk of weight gain and metabolic syndrome (Prajapati ). Clozapine is indicated for people living with a diagnosis of schizophrenia or schizoaffective disorder who have not responded to, or who are intolerant of, other antipsychotic medicines.…”

Developing a metformin prescribing tool for use in adults with mental illness to reduce medication-related weight gain and cardiovascular risk

“…20 Barriers to prescribing metformin in patients with severe mental illness may include lack of knowledge and familiarity with metformin, concern about side effects and hesitancy to prescribe metformin outside of PBS-approved use. Although there are existing guidelines 17–19 that include instructions for prescribing ‘off-label’ metformin in order to address SGA-induced weight gain, PCOS, and glucose dysregulation, the development of a specific treatment protocol for metformin has been suggested 21 in order to promote wider uptake of a safe and effective intervention. Given the evidence to support the use of metformin to reduce SGA-associated weight gain and cardiovascular risk, the aim of this study was to develop an easy-to-use metformin prescribing tool for use in adults with mental illness to reduce weight gain.…”