Extended release metformin for metabolic control assistance during prolonged clozapine administration: a 14 week, double-blind, parallel group, placebo-controlled study

The Optimal Dosage and Duration of Metformin for Prevention and Treatment of Antipsychotic-Induced Weight Gain: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Weight gain and metabolic complications are substantial adverse effects associated with second-generation antipsychotics. However, comprehensive guidelines for managing antipsychotic-induced weight gain are lacking.

METHODS

This review included all double-blind, placebo-controlled studies investigating metformin's effectiveness in addressing antipsychotic-related weight gain. We systematically searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, Google Scholar, and ClinicalTrials.gov for relevant studies from the inception to 2024. A random-effects model was used for the meta-analysis.

RESULTS

This meta-analysis, including 20 studies with 1070 patients, revealed that metformin significantly surpassed placebo in attenuating weight gain in patients receiving antipsychotics. The mean weight change with metformin was -3.32 kg [95% confidence interval (CI): -4.57 to -2.07]. Additionally, metformin use resulted in a marked decrease in body mass index [-1.24 kg/m2 (95% CI: -1.70 to -0.77)]. Metformin could maintain the effects from 12 to 24 weeks.

CONCLUSIONS

This updated meta-analysis investigated the durations and dosages of metformin use in patients with schizophrenia experiencing antipsychotic-induced weight gain. The findings highlight the need for additional large-scale research to validate our findings.

Pharmacological interventions for antipsychotic-induced weight gain in schizophrenia: A network meta-analysis

OBJECTIVE

Antipsychotic-induced weight gain (AIWG) is a significant but frequently neglected adverse effect of first- and second-generation antipsychotic therapy, which may lead to cardiovascular disturbances. The present network meta-analysis (NMA) was conducted to evaluate and compare the effects of available treatment options in antipsychotic-induced weight gain (AIWG).

METHODS

The data was extracted from 68 relevant clinical trials after a literature search on MEDLINE/PubMed, Embase, Scopus, Cochrane databases and clinical trial registries. Random-effects Bayesian NMA was done to pool the effects across the interventions for the change in body weight from baseline. A network graph was built, a consistency model was run, node split analysis was performed, treatments were ranked as per the SUCRA score and meta-regression was done for the duration of therapy, baseline body weight and treatment strategy as the predictor variables. Finally, the results were sorted based on the certainty of evidence.

RESULTS

The drugs showing significant reduction in body weight in order of magnitude of effect size include sibutramine 10 mg (-8.0 kg; -16. to -0.21), metformin 750 mg + lifestyle modification (-7.5 kg; -12 to -2.8), topiramate 200 mg (-7 kg; -10 to -3.4), metformin 750 mg (-5.7 kg; -9.3 to -2.1), topiramate 100 mg (-5.7 kg; -8.8 to -2.5), topiramate 50 mg (-5.2 kg; -10 to -0.57), liraglutide 1.8 mg (-5.2 kg; -10., -0.080), sibutramine 15 mg (-4.5 kg; -8.9 to -0.59), nizatidine 300 mg (-3.0 kg; -5.9 to -0.23) and metformin 1000 mg (-2.3 kg; -4.6 to -0.0046). There was no effect of duration of follow-up, baseline body weight and, preventive versus therapeutic strategy on weight reduction in AIWG.

CONCLUSION

Metformin 750 mg with lifestyle modification was the most effective treatment for AIWG, followed by topiramate 200 mg, metformin 750 mg, and topiramate 100 mg with moderate certainty of evidence.

Clozapine safety monitoring and related research in psychiatry and neurology in South America: A scoping review

The quality and quantity of clozapine safety monitoring considerably differs among South American countries and mainly focus on hematological surveillance. Few studies have been conducted on other clozapine-related adverse effects (ADRs) and mainly refer to case reports and literature reviews. We retrieved thirty-nine publications on clozapine related ADRs others than neutropenia. Studies in Brazil and Venezuela accounted for 67 % of all the publications, and 8 out of 12 countries published 2 or less manuscripts. Only Chile offers serum clozapine level measurement in public institutions. Given the recently recognized role of ethnicity, gender, smoking, obesity drug interactions in optimal clozapine administration, modernization of clozapine clinical use and research in psychiatry and neurology most be broadcasted and stimulated in South American countries.

The Tarnished Legacy of a Wonder Drug: Revisiting the Complicated History of Clozapine

Anecdotal evidence of superior efficacy and lack of extrapyramidal symptoms in treating schizophrenia made clozapine a promising therapy in the United States during the early 1970s. In 1975, however, numerous fatal cases of clozapine-related agranulocytosis in Finland nearly ended the drug's development. Convinced of the significant benefits to patients, some clinicians in the United States advocated having clozapine available on a case-by-case humanitarian basis, which eventually helped resurrect the drug for Food and Drug Administration approval in 1989. This article builds on previous literature by utilizing oral histories from clinicians, researchers, and a patient's family member to understand how clozapine was saved. Exploring these stakeholders' perspectives has value to modern clinicians, who underprescribe the drug despite demonstrable benefits for treatment-resistant schizophrenia and suicide prevention.

The potential effect of metformin on cognitive and other symptom dimensions in patients with schizophrenia and antipsychotic-induced weight gain: a systematic review, meta-analysis, and meta-regression

Introduction

Metformin has shown good efficacy in the management of antipsychotic-induced metabolic syndrome (MetS) in patients with schizophrenia or schizoaffective disorders. Its ability to induce antidepressant behavioural effects and improve cognitive functions has also been investigated: yet information has not been systematized. The aim of this study was therefore to investigate the effects of metformin on cognitive and other symptom dimension in schizophrenic patients treated with antipsychotics through a systematic review and meta-analysis.

Methods

We searched PubMed, ClinicalTrials.Gov, Embase, PsycINFO, and WHO ICTRP database up to February 2022, Randomised Controlled Trials (RCT) evaluating patients diagnosed with schizophrenia and related disorders, who were treated with metformin as add-on therapy to antipsychotics for the treatment of weight gain and in which changes in psychiatric symptoms and cognitive functions were evaluated.

Results

A total of 19 RCTs met the inclusion criteria. Meta-analysis was performed on 12 eligible studies. We found a positive trend after 24 weeks of treatment in schizophrenic patients with stable conditions [SMD (95%CI) = -0.40 (-0.82;0.01), OR (95%CI) = 0.5 (-2.4;3.4)]. Better performance was detected in the Brief Assessment of Cognition in Schizophrenia and Positive and Negative Syndrome Scale (PANSS) with low heterogeneity among studies. One study reported changes in BACS-verbal memory subdomain in favour of placebo [MD (95%CI) = -16.03 (-23.65;8.42)]. Gastrointestinal disorders, xerostomia, and extrapyramidal syndrome were the most reported adverse effects. Psychiatric adverse events were also described: in particular, symptoms attributable to a relapse of schizophrenia.

Conclusion

Some degree of efficacy was found for Metformin in improving cognitive and other symptom dimensions in patients with Schizophrenia. Given the clinical relevance of this potential pharmacological effect, longer specific studies using adequate psychometric scales are strongly recommended. Likewise, how metformin acts in this context needs to be evaluated in order to enhance its efficacy or find more efficacious drugs.

Pharmacological interventions for prevention of weight gain in people with schizophrenia

BACKGROUND

Antipsychotic-induced weight gain is an extremely common problem in people with schizophrenia and is associated with increased morbidity and mortality. Adjunctive pharmacological interventions may be necessary to help manage antipsychotic-induced weight gain. This review splits and updates a previous Cochrane Review that focused on both pharmacological and behavioural approaches to this problem.

OBJECTIVES

To determine the effectiveness of pharmacological interventions for preventing antipsychotic-induced weight gain in people with schizophrenia.

SEARCH METHODS

The Cochrane Schizophrenia Information Specialist searched Cochrane Schizophrenia's Register of Trials on 10 February 2021. There are no language, date, document type, or publication status limitations for inclusion of records in the register.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that examined any adjunctive pharmacological intervention for preventing weight gain in people with schizophrenia or schizophrenia-like illnesses who use antipsychotic medications.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed the quality of included studies. For continuous outcomes, we combined mean differences (MD) in endpoint and change data in the analysis. For dichotomous outcomes, we calculated risk ratios (RR). We assessed risk of bias for included studies and used GRADE to judge certainty of evidence and create summary of findings tables. The primary outcomes for this review were clinically important change in weight, clinically important change in body mass index (BMI), leaving the study early, compliance with treatment, and frequency of nausea. The included studies rarely reported these outcomes, so, post hoc, we added two new outcomes, average endpoint/change in weight and average endpoint/change in BMI.

MAIN RESULTS

Seventeen RCTs, with a total of 1388 participants, met the inclusion criteria for the review. Five studies investigated metformin, three topiramate, three H2 antagonists, three monoamine modulators, and one each investigated monoamine modulators plus betahistine, melatonin and samidorphan. The comparator in all studies was placebo or no treatment (i.e. standard care alone). We synthesised all studies in a quantitative meta-analysis. Most studies inadequately reported their methods of allocation concealment and blinding of participants and personnel. The resulting risk of bias and often small sample sizes limited the overall certainty of the evidence. Only one reboxetine study reported the primary outcome, number of participants with clinically important change in weight. Fewer people in the treatment condition experienced weight gains of more than 5% and more than 7% of their bodyweight than those in the placebo group (> 5% weight gain RR 0.27, 95% confidence interval (CI) 0.11 to 0.65; 1 study, 43 participants; > 7% weight gain RR 0.24, 95% CI 0.07 to 0.83; 1 study, 43 participants; very low-certainty evidence). No studies reported the primary outcomes, 'clinically important change in BMI', or 'compliance with treatment'. However, several studies reported 'average endpoint/change in body weight' or 'average endpoint/change in BMI'. Metformin may be effective in preventing weight gain (MD -4.03 kg, 95% CI -5.78 to -2.28; 4 studies, 131 participants; low-certainty evidence); and BMI increase (MD -1.63 kg/m2, 95% CI -2.96 to -0.29; 5 studies, 227 participants; low-certainty evidence). Other agents that may be slightly effective in preventing weight gain include H2 antagonists such as nizatidine, famotidine and ranitidine (MD -1.32 kg, 95% CI -2.09 to -0.56; 3 studies, 248 participants; low-certainty evidence) and monoamine modulators such as reboxetine and fluoxetine (weight: MD -1.89 kg, 95% CI -3.31 to -0.47; 3 studies, 103 participants; low-certainty evidence; BMI: MD -0.66 kg/m2, 95% CI -1.05 to -0.26; 3 studies, 103 participants; low-certainty evidence). Topiramate did not appear effective in preventing weight gain (MD -4.82 kg, 95% CI -9.99 to 0.35; 3 studies, 168 participants; very low-certainty evidence). For all agents, there was no difference between groups in terms of individuals leaving the study or reports of nausea. However, the results of these outcomes are uncertain given the very low-certainty evidence.

AUTHORS' CONCLUSIONS

There is low-certainty evidence to suggest that metformin may be effective in preventing weight gain. Interpretation of this result and those for other agents, is limited by the small number of studies, small sample size, and short study duration. In future, we need studies that are adequately powered and with longer treatment durations to further evaluate the efficacy and safety of interventions for managing weight gain.

Metformin for the prevention of clozapine-induced weight gain: A retrospective naturalistic cohort study

OBJECTIVE

Clozapine is presently the sole antipsychotic with an indication for treatment-resistant Schizophrenia, but is associated with significant weight gain and other metabolic aberrations. This retrospective chart review aimed to evaluate the effectiveness of adjunctive metformin in preventing clozapine-induced weight gain.

METHODS

We conducted a retrospective chart review of patients newly initiated on clozapine at the Centre for Addiction and Mental Health in Canada, from November 2014 to April 2021. Our primary outcome was body weight at 6 and 12 months after clozapine initiation. Other metabolic parameters served as secondary outcomes.

RESULTS

Among 396 patients (males: 71.5%, mean age: 42.8 years) initiated on clozapine, 69 were on metformin or prescribed it ≤3 months after clozapine initiation. The clozapine+metformin group demonstrated less weight gain compared with the clozapine-only group at 6 months (clozapine+metformin: -0.15 kg [SE = 1.08] vs. clozapine-only: 2.99 kg, SE = 0.54) and 12 months after clozapine initiation (clozapine+metformin: -0.67 kg, SE = 1.22 vs. clozapine-only: 4.72 kg, SE = 0.67). Adaptive changes were also observed for fasting glucose (F = 3.10, p = 0.046) and triglycerides (F = 8.56, p < 0.001) in the clozapine+metformin group compared with clozapine only.

CONCLUSION

In this large retrospective naturalistic cohort study, co-prescription of clozapine and metformin was associated with less weight gain and related metabolic dysfunction at 6 and 12 months after initiation versus clozapine alone. These findings provide evidence for the effectiveness of metformin in preventing clozapine-induced weight gain; larger randomized controlled trials are needed to confirm these results.

Pharmacological Management of Glucose Dysregulation in Patients Treated with Second-Generation Antipsychotics

Fasting hyperglycemia, impaired glucose tolerance, prediabetes, and diabetes are frequently present in patients treated with second-generation antipsychotics (SGAPs) for schizophrenia, bipolar disorder, and other severe mental illnesses. These drugs are known to produce weight gain, which may lead to insulin resistance, glucose intolerance, and metabolic syndrome, which constitute important risk factors for the emergence of diabetes. The aim of this review was to formulate therapeutic guidelines for the management of diabetes in patients treated with SGAPs, based on the association between SGAP-induced weight gain and glucose dysregulation. A  systematic search in PubMed from inception to March 2020 for randomized controlled trials (RCTs) of diabetes or prediabetes in patients treated with SGAPs was performed. PubMed was also searched for the most recent clinical practice guidelines of interventions for co-morbid conditions associated with diabetes mellitus (DM) (arterial hypertension and dyslipidemia), lifestyle interventions and switching from high metabolic liability SGAPs to safer SGAPs. The search identified 14 RCTs in patients treated with SGAPs. Drug therapy using metformin as first-line therapy and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) or perhaps sodium-glucose cotransporter-2 (SGLT2) inhibitors as add-on therapy, might be preferred in these patients as well, as they favorably influence glucose metabolism and body mass index, and provide cardio-renal benefits in general to the DM population, although for the SGLT-2 inhibitors there are no RCTs in this specific patient category so far. Metformin is also useful for treatment of prediabetes. Arterial hypertension should be treated with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and statins should be used for correction of dyslipidemia. The outcome of lifestyle-changing interventions has been disappointing. Switching from clozapine, olanzapine, or quetiapine to lower cardiometabolic-risk SGAPs, like aripiprazole, brexpiprazole, cariprazine, lurasidone, or ziprasidone, has been recommended.

A ganglionic blocker and adrenoceptor ligands modify clozapine-induced insulin resistance

Clozapine is a second generation antipsychotic drug that has proven to be helpful in the management of patients with psychotic disorders that are resistant to other medications. Unfortunately, the majority of patients treated with clozapine develop metabolic dysregulation, including weight gain and insulin resistance. There are few treatments available to effectively counter these side-effects. The goal of the present study was to use an established animal model to better understand the nature of these metabolic side-effects and determine whether existing drugs could be used to alleviate metabolic changes. Adult female rats were treated with a range of doses of clozapine (2, 10 and 20 mg/kg) and subjected to the hyperinsulinemic-euglycemic clamp, to measure whole-body insulin resistance. Clozapine dose-dependently decreased the glucose infusion rate, reflecting pronounced insulin resistance. To reverse the insulin resistance, rats were co-treated with the ganglionic blocker mecamylamine (0.1, 1.0 and 5.0 mg/kg) which dose-dependently reversed the effects of 10 mg/kg clozapine. A 1.0 mg/kg dose of mecamylamine independently reversed the large increase in peripheral epinephrine caused by treatment with clozapine. To study the influence of specific adrenoceptors, rats were treated with multiple doses of α₁ (prazosin), α₂ (idazoxan), β₁ (atenolol) and β₂ (butoxamine) adrenoceptor antagonists after the onset of clozapine-induced insulin resistance. Both beta blockers were effective in attenuating the effects of clozapine, while idazoxan had a smaller effect; no change was seen with prazosin. The current results indicate that peripheral catecholamines may play a role in clozapine's metabolic effects and be a target for future treatments.

Is Sitagliptin Effective for Modulating Metabolic Disturbances Associated With Olanzapine in Schizophrenia Patients? A Double-blind Placebo-controlled Clinical Trial

PURPOSE/BACKGROUND

The mortality rate of patients with schizophrenia due to metabolic disturbances is high. Our aim is to survey the effects of sitagliptin on metabolic disturbances associated with olanzapine in patients with schizophrenia.

METHODS/PROCEDURES

In this 12-week double-blind placebo-controlled clinical trial, 71 patients taking olanzapine (10 to 30 mg) for at least 1 month were randomly allocated to enter 1 of the 2 treatment groups (olanzapine plus placebo or olanzapine plus sitagliptin). Sitagliptin was added to patients 'current medications with the dose of 100 mg/d. Physical examinations and measurement of anthropometric (body mass index and waist circumference) and laboratory parameters (fasting blood sugar, glycated hemoglobin, total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglyceride) were measured at baseline, week 4, and week 12. The patients were assessed for any side effects of the medications in each visit.

FINDINGS/RESULTS

Sixty-one patients (30 in the sitagliptin and 31 in the placebo group) completed the trial. The anthropometric measurements at the end of the study did not differ between the 2 groups. glycated hemoglobin and total cholesterol were significantly lower in the sitagliptin group after 12 weeks. Other metabolic profile revealed either no change or minimal magnitude changes. No major side effect was reported.

IMPLICATIONS/CONCLUSIONS

Metabolic disturbances associated with olanzapine treatment in patients with schizophrenia can be modulated by sitagliptin.

Atypical Antipsychotics and Metabolic Syndrome: From Molecular Mechanisms to Clinical Differences

Atypical antipsychotics (AAPs) are commonly prescribed medications to treat schizophrenia, bipolar disorders and other psychotic disorders. However, they might cause metabolic syndrome (MetS) in terms of weight gain, dyslipidemia, type 2 diabetes (T2D), and high blood pressure, which are responsible for reduced life expectancy and poor adherence. Importantly, there is clear evidence that early metabolic disturbances can precede weight gain, even if the latter still remains the hallmark of AAPs use. In fact, AAPs interfere profoundly with glucose and lipid homeostasis acting mostly on hypothalamus, liver, pancreatic β-cells, adipose tissue, and skeletal muscle. Their actions on hypothalamic centers via dopamine, serotonin, acetylcholine, and histamine receptors affect neuropeptides and 5'AMP-activated protein kinase (AMPK) activity, thus producing a supraphysiological sympathetic outflow augmenting levels of glucagon and hepatic glucose production. In addition, altered insulin secretion, dyslipidemia, fat deposition in the liver and adipose tissues, and insulin resistance become aggravating factors for MetS. In clinical practice, among AAPs, olanzapine and clozapine are associated with the highest risk of MetS, whereas quetiapine, risperidone, asenapine and amisulpride cause moderate alterations. The new AAPs such as ziprasidone, lurasidone and the partial agonist aripiprazole seem more tolerable on the metabolic profile. However, these aspects must be considered together with the differences among AAPs in terms of their efficacy, where clozapine still remains the most effective. Intriguingly, there seems to be a correlation between AAP's higher clinical efficacy and increase risk of metabolic alterations. Finally, a multidisciplinary approach combining psychoeducation and therapeutic drug monitoring (TDM) is proposed as a first-line strategy to avoid the MetS. In addition, pharmacological treatments are discussed as well.

Interventions for preventing type 2 diabetes in adults with mental disorders in low- and middle-income countries

BACKGROUND

The prevalence of type 2 diabetes is increased in individuals with mental disorders. Much of the burden of disease falls on the populations of low- and middle-income countries (LMICs).

OBJECTIVES

To assess the effects of pharmacological, behaviour change, and organisational interventions versus active and non-active comparators in the prevention or delay of type 2 diabetes among people with mental illness in LMICs.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register, CENTRAL, MEDLINE, Embase and six other databases, as well as three international trials registries. We also searched conference proceedings and checked the reference lists of relevant systematic reviews. Searches are current up to 20 February 2020.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of pharmacological, behavioural or organisational interventions targeting the prevention or delay of type 2 diabetes in adults with mental disorders in LMICs.

DATA COLLECTION AND ANALYSIS

Pairs of review authors working independently performed data extraction and risk of bias assessments. We conducted meta-analyses using random-effects models.

MAIN RESULTS

One hospital-based RCT with 150 participants (99 participants with schizophrenia) addressed our review's primary outcome of prevention or delay of type 2 diabetes onset. Low-certainty evidence from this study did not show a difference between atypical and typical antipsychotics in the development of diabetes at six weeks (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.03 to 7.05) (among a total 99 participants with schizophrenia, 68 were in atypical and 31 were in typical antipsychotic groups; 55 participants without mental illness were not considered in the analysis). An additional 29 RCTs with 2481 participants assessed one or more of the review's secondary outcomes. All studies were conducted in hospital settings and reported on pharmacological interventions. One study, which we could not include in our meta-analysis, included an intervention with pharmacological and behaviour change components. We identified no studies of organisational interventions. Low- to moderate-certainty evidence suggests there may be no difference between the use of atypical and typical antipsychotics for the outcomes of drop-outs from care (RR 1.31, 95% CI 0.63 to 2.69; two studies with 144 participants), and fasting blood glucose levels (mean difference (MD) 0.05 lower, 95% CI 0.10 to 0.00; two studies with 211 participants). Participants who receive typical antipsychotics may have a lower body mass index (BMI) at follow-up than participants who receive atypical antipsychotics (MD 0.57, 95% CI 0.33 to 0.81; two studies with 141 participants; moderate certainty of evidence), and may have lower total cholesterol levels eight weeks after starting treatment (MD 0.35, 95% CI 0.27 to 0.43; one study with 112 participants). There was moderate certainty evidence suggesting no difference between the use of metformin and placebo for the outcomes of drop-outs from care (RR 1.22, 95% CI 0.09 to 16.35; three studies with 158 participants). There was moderate-to-high certainty evidence of no difference between metformin and placebo for fasting blood glucose levels (endpoint data: MD -0.35, 95% CI -0.60 to -0.11; change from baseline data: MD 0.01, 95% CI -0.21 to 0.22; five studies with 264 participants). There was high certainty evidence that BMI was lower for participants receiving metformin compared with those receiving a placebo (MD -1.37, 95% CI -2.04 to -0.70; five studies with 264 participants; high certainty of evidence). There was no difference between metformin and placebo for the outcomes of waist circumference, blood pressure and cholesterol levels. Low-certainty evidence from one study (48 participants) suggests there may be no difference between the use of melatonin and placebo for the outcome of drop-outs from care (RR 1.00, 95% CI 0.38 to 2.66). Fasting blood glucose is probably reduced more in participants treated with melatonin compared with placebo (endpoint data: MD -0.17, 95% CI -0.35 to 0.01; change from baseline data: MD -0.24, 95% CI -0.39 to -0.09; three studies with 202 participants, moderate-certainty evidence). There was no difference between melatonin and placebo for the outcomes of waist circumference, blood pressure and cholesterol levels. Very low-certainty evidence from one study (25 participants) suggests that drop-outs may be higher in participants treated with a tricyclic antidepressant (TCA) compared with those receiving a selective serotonin reuptake inhibitor (SSRI) (RR 0.34, 95% CI 0.11 to 1.01). It is uncertain if there is no difference in fasting blood glucose levels between these groups (MD -0.39, 95% CI -0.88 to 0.10; three studies with 141 participants, moderate-certainty evidence). It is uncertain if there is no difference in BMI and depression between the TCA and SSRI antidepressant groups.

AUTHORS' CONCLUSIONS

Only one study reported data on our primary outcome of interest, providing low-certainty evidence that there may be no difference in risk between atypical and typical antipsychotics for the outcome of developing type 2 diabetes. We are therefore not able to draw conclusions on the prevention of type 2 diabetes in people with mental disorders in LMICs. For studies reporting on secondary outcomes, there was evidence of risk of bias in the results. There is a need for further studies with participants from LMICs with mental disorders, particularly on behaviour change and on organisational interventions targeting prevention of type 2 diabetes in these populations.

Pharmacological Interventions to Treat Antipsychotic-Induced Dyslipidemia in Schizophrenia Patients: A Systematic Review and Meta Analysis

Introduction: Antipsychotic-induced dyslipidemia represents a common adverse effect faced by patients with schizophrenia that increases risk for developing further metabolic complications and cardiovascular disease. Despite its burden, antipsychotic-induced dyslipidemia is often left untreated, and the effectiveness of pharmacological interventions for mitigating dyslipidemia has not been well-addressed. This review aims to assess the effectiveness of pharmacological interventions in alleviating dyslipidemia in patients with schizophrenia. Methods: Medline, PsychInfo, and EMBASE were searched for all relevant English articles from 1950 to November 2020. Randomized placebo-controlled trials were included. Differences in changes in triglycerides, HDL cholesterol, LDL cholesterol, and VLDL cholesterol levels between treatment and placebo groups were meta-analyzed as primary outcomes. Results: Our review identified 48 randomized controlled trials that comprised a total of 3,128 patients and investigated 29 pharmacological interventions. Overall, pharmacological interventions were effective in lowering LDL cholesterol, triglycerides, and total cholesterol levels while increasing the levels of HDL cholesterol. Within the intervention subgroups, approved lipid-lowering agents did not reduce lipid parameters other than total cholesterol level, while antipsychotic switching and antipsychotic add-on interventions improved multiple lipid parameters, including triglycerides, LDL cholesterol, HDL cholesterol, and total cholesterol. Off label lipid lowering agents improved triglycerides and total cholesterol levels, with statistically significant changes seen with metformin. Conclusion: Currently available lipid lowering agents may not work as well in patients with schizophrenia who are being treated with antipsychotics. Additionally, antipsychotic switching, antipsychotic add-ons, and certain off label interventions might be more effective in improving some but not all associated lipid parameters. Future studies should explore novel interventions for effectively managing antipsychotic-induced dyslipidemia. Registration: PROSPERO 2020 CRD42020219982; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020219982.

A Review of Switching Strategies for Patients with Schizophrenia Comorbid with Metabolic Syndrome or Metabolic Abnormalities

Metabolic syndrome (MetS) in patients with schizophrenia occurs 2-3 times more frequently than in the general population. Antipsychotic medication is a primary risk factor for patients with MetS. In particular, the widely used second-generation antipsychotics can affect glucose and lipid metabolism and can induce insulin resistance and other metabolic abnormalities through various receptors. Notably, the metabolic risks of various antipsychotics may differ because of their different pharmacological affinity to MetS-related receptors. Several previous studies have shown that switching from high to low metabolic risk antipsychotics may improve patients' metabolic parameters. The current review aims to discuss the strategies for switching antipsychotic medications and the impact on metabolic abnormalities in patients with schizophrenia.

Time course and dose effect of metformin on weight in patients with different disease states

OBJECTIVES

The present study was to quantitate and compare the efficacy of metformin on weight in different disease states using model-based meta-analysis (MBMA).

METHODS

Randomized controlled trials (RCT) of metformin effects on weight in different disease states were collected by searching the public databases. The change rate of weight from baseline was selected as the efficacy indicator.

RESULTS

A total 21 RCTs containing 1885 patients including patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity, were included into the present study. After deducting placebo effect, the maximal effect (E_max) of metformin on weight in patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity were -6.86%, -8.82%, and -4.14%, respectively. The treatment duration to reach half of the maximal effect (ET₅₀) were 107, 45.5, and 15.1 weeks, respectively. Within the metformin dose range from 21 RCTs, no significant dose-response relationship was observed. However, the time-course relationship is obvious for efficacy of metformin on weight.

CONCLUSIONS

The present study firstly provided quantitative information for metformin effects on weight in different disease states, including patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity.

Adjunctive metformin for antipsychotic-induced dyslipidemia: a meta-analysis of randomized, double-blind, placebo-controlled trials

Antipsychotic-induced dyslipidemia could increase the risk of cardiovascular diseases. This is a meta-analysis of randomized double-blind placebo-controlled trials to examine the efficacy and safety of adjunctive metformin for dyslipidemia induced by antipsychotics in schizophrenia. The standardized mean differences (SMDs) and risk ratios (RRs) with their 95% confidence intervals (CIs) were calculated using the random-effects model with the RevMan 5.3 version software. The primary outcome was the change of serum lipid level. Twelve studies with 1215 schizophrenia patients (592 in metformin group and 623 in placebo group) were included and analyzed. Adjunctive metformin was significantly superior to placebo with regards to low density lipoprotein cholesterol (LDL-C) [SMD: -0.37 (95%CI:-0.69, -0.05), P = 0.02; I² = 78%], total cholesterol [SMD: -0.47 (95%CI:-0.66, -0.29), P < 0.00001; I² = 49%], triglyceride [SMD: -0.33 (95%CI:-0.45, -0.20), P < 0.00001; I² = 0%], and high density lipoprotein cholesterol [SMD: 0.29 (95%CI:0.02, 0.57), P = 0.03; I² = 69%]. The superiority of metformin in improving LDL-C level disappeared in a sensitivity analysis and 80% (8/10) of subgroup analyses. Metformin was significantly superior to placebo with regards to decrease in body weight, body mass index, glycated hemoglobin A1c, fasting insulin, and homeostasis model assessment-insulin resistance (P = 0.002-0.01), but not regarding changes in waist circumference, waist-to-hip rate, leptin, fasting glucose, and blood pressure (P = 0.07-0.33). The rates of discontinuation due to any reason [RR: 0.97 (95%CI: 0.66, 1.43), P = 0.89; I² = 0%] was similar between the two groups. Adjunctive metformin could be useful to improve total cholesterol and triglyceride levels, but it was not effective in improving LDL-C level in schizophrenia.

How and when to use clozapine

OBJECTIVE

Clozapine is the only approved strategy for treatment-resistant schizophrenia, although it is highly underutilized. We aim to generate practical and actionable evidence-based recommendations for the use of this drug considering prescription barriers.

METHOD

Narrative review.

RESULTS

A consistent body of evidence supports the efficacy of clozapine reducing morbidity and mortality in schizophrenia. The main obstacles to its use are the lack of experience by prescribers and perceived treatment burden. Systematic screening of eligibility, utilization of available resources for consultation, developing a professional network with other stakeholders, as well as optimizing how clozapine is presented to patients is discussed. Furthermore, specific evidence-based recommendations for initiation, maintenance, and safety monitoring with clozapine are provided.

CONCLUSION

Clozapine prescription is one of the areas in psychiatry with the greatest mismatch between efficacy and utilization in clinical practice. Although multiple barriers to the use of clozapine exist, some of these may be overcome by updates of routine clinical practice.

The clozapine to norclozapine ratio: a narrative review of the clinical utility to minimize metabolic risk and enhance clozapine efficacy

Introduction: Clozapine remains the most effective antipsychotic for treatment-refractory schizophrenia. However, ~40% of the patients respond insufficiently to clozapine. Clozapine's effects, both beneficial and adverse, have been proposed to be partially attributable to its main metabolite, N-desmethylclozapine (NDMC). However, the relation of the clozapine to norclozapine ratio (CLZ:NDMC; optimally defined as ~2) to clinical response and metabolic outcomes is not clear.Areas covered: This narrative review comprehensively examines the clinical utility of the CLZ:NDMC ratio to reduce metabolic risk and increase treatment efficacy. The association of the CLZ:NDMC ratio with changes in psychopathology, cognitive functioning, and cardiometabolic burden will be explored, as well as adjunctive treatments and their effects.Expert opinion: The literature suggests a positive association between the CLZ:NDMC ratio and better cardiometabolic outcomes. Conversely, the CLZ:NDMC ratio appears inversely associated with better cognitive functioning but less consistently with other psychiatric domains. The CLZ:NDMC ratio may be useful for predicting and monitoring cardiometabolic adverse effects and optimizing potential cognitive benefits of clozapine. Future studies are required to replicate these findings, which if substantiated, would encourage examination of adjunctive treatments aiming to alter the CLZ:NDMC ratio to best meet the needs of the individual patient, thereby broadening clozapine's clinical utility.

Second generation antipsychotic-induced weight gain in youth with autism spectrum disorders: a brief review of mechanisms, monitoring practices, and indicated treatments

The purpose of this review was to understand the impact of second generation antipsychotic (SGA)-induced weight gain on youth with autism spectrum disorders (ASDs), including the clinical evidence, mechanisms, monitoring guidelines, and treatments. To achieve this, multiple MEDLINE/PUBMED and Google database searches were performed and analyzed articles from January 2001 to April 2018. Existing evidences indicates youth with ASDs may be more prone to SGA-induced weight gain than youth with other psychiatric illnesses. The mechanism by which such weight gain occurs is unclear, but is likely multifactorial. Guidelines have been developed to monitor SGA-induced weight gain, though the existing guidelines have had limited adherence by clinicians. The available randomized control trials that have analyzed the benefit of metformin in youth suffering from SGA-induced weight gain have produced conflicting results, but the data looking specifically at youth with ASD have been positive. Increasing data on use of topiramate, melatonin, and zonisamide to treat SGA-induced weight gain in youth also exists and warrants further study. However, overall, the current understanding of the effect of SGA-induced weight gain on youth with ASD and the therapeutic use of medications like metformin is limited, but the existing literature provides useful guidelines for future research. The clinical algorithms for monitoring and managing SGA-induced weight gain have shown promise; however, their utility in routine clinical practice requires further investigation.

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

Background: Antipsychotic drugs may lead to side effects such as obesity, diabetes, dyslipidemia, and cardiovascular disease. The current systematic review and network meta-analysis analyzes and provides an update on the clinical performance of these add-ons in comparison to placebo on body weight and body mass index (BMI) reductions. Methods: A comprehensive literature search was performed on electronic databases: PubMed (1946-), Embase (1974-), Cochrane library (1992-), and OpenGrey (2000-) until 31 July 2018. Network meta-analyses, comparing the body weight change, BMI change and withdrawn due to adverse events of different pharmacological add-ons, was performed using a multivariate meta-regression model with random-effects, adopting a frequentist approach. To rank the prognosis for all add-ons, we used surface under the cumulative ranking (SUCRA) values. Outcomes: From 614 potential studies identified, 27 eligible studies (n = 1,349 subjects) were included. All the studies demonstrated low to moderate risk of bias. For the analysis of body weight change, all add-ons except Ranitidine showed significant weight reductions comparing to placebo. The effectiveness rank based on SUCRA results from highest to lowest was Sibutramine, Topiramate, Metformin, Reboxetine, Ranitidine, and placebo. A similar pattern was seen for BMI change. The analysis of safety outcome did not detect significantly increased withdrawn number from the add-ons. Current evidence showed relatively good tolerance and safety of using the pharmacological add-ons. Interpretation: Topiramate and Metformin are effective add-on treatments in controlling antipsychotic-induced weight gain, comparing to placebo. They are well tolerated in short-term period. Although Sibutramine has the highest rank of the effectiveness, its license has been withdrawn in many countries due to its adverse effects. Hence, Sibutramine should not be adopted to treat antipsychotic-induced weight gain.

Using clozapine in clinical practice

Clozapine remains underutilised as the only antipsychotic for treatment-resistant schizophrenia, despite liberal National Institute for Health and Clinical Excellence guidelines for its consideration. Bearing in mind its monitoring requirements and poor tolerability, suggestions are made for patients who fail to improve on other antipsychotic drugs. Clozapine may be offered to apparently unsuitable patients, although this is fraught with difficulty. A realistic appraisal of the alternatives is essential in this situation. Optimising plasma clozapine levels, alongside the use of rehabilitative interventions and adjuncts as necessary, will maximise efficacy, and there are numerous options to minimise side-effects. Clozapine requires a lengthier trial than other antipsychotics and discontinuation should be avoided if possible, as the results are generally very poor. Established successful clozapine treatment can induce substantial functional gains which accrue with time: patients are retained in treatment and relapse is prevented. Such optimal outcomes justify the initial effort expended by all.

Efficacy of Metformin and Topiramate in Prevention and Treatment of Second-Generation Antipsychotic–Induced Weight Gain

Objective

To review the literature describing the efficacy of metformin and topiramate for the treatment of second-generation antipsychotio–induced weight gain.

Data sources

Articles were identified by searching the MEDLINE database (from 1949 through January 2010) using the key words metformin, topiramate, antipsychotic, weight, weight gain, and obesity.

Study selection and data extraction

All randomized, place bo-controlled trials of metformin and topiramate were selected for review.

Data synthesis

Weight gain due to second-generation antipsychotic use is a concern due to the risk of long-term metabolic and cardiovascular effects with these agents. These effects include obesity, hyperglycemia, and insulin resistance, all of which may contribute to diabetes and cardiovascular disease. Second-generation antipsychotics vary in the degree to which they cause weight gain, and dietary and lifestyle changes may not be feasible or sufficient in counteracting this weight gain. Although other pharmacologic agents may be beneficial to prevent and treat antipsychotic-induced weight gain, metformin and topiramate have been the most extensively studied in this setting. Metformin acts peripherally to cause weight loss, while topiramate acts centrally. Review of 11 randomized, controlled trials demonstrates beneficial effects of metformin and topiramate in prevention and treatment of weight gain. Metformin is generally well tolerated and has been studied in pediatric patients, while topiramate is associated with more drug interactions and may possibly interfere with control of schizophrenia.

Conclusions

Data for the use of metformin and topiramate in the treatment and prevention of second-generation antipsychotio–induced weight gain are limited. Both may be effective in helping patients lose weight via mechanisms that have yet to be clearly defined. The use of metformin results in greater weight loss than topiramate, and topiramate is associated with more risks and may compromise the treatment of schizophrenia. Treatment of antipsychotic-induced weight gain with metformin may be an option after lifestyle and dietary changes have failed.

The Effectiveness of Pharmacological and Non-Pharmacological Interventions for Improving Glycaemic Control in Adults with Severe Mental Illness: A Systematic Review and Meta-Analysis

People with severe mental illness (SMI) have reduced life expectancy compared with the general population, which can be explained partly by their increased risk of diabetes. We conducted a meta-analysis to determine the clinical effectiveness of pharmacological and non-pharmacological interventions for improving glycaemic control in people with SMI (PROSPERO registration: CRD42015015558). A systematic literature search was performed on 30/10/2015 to identify randomised controlled trials (RCTs) in adults with SMI, with or without a diagnosis of diabetes that measured fasting blood glucose or glycated haemoglobin (HbA_1c). Screening and data extraction were carried out independently by two reviewers. We used random effects meta-analysis to estimate effectiveness, and subgroup analysis and univariate meta-regression to explore heterogeneity. The Cochrane Collaboration’s tool was used to assess risk of bias. We found 54 eligible RCTs in 4,392 adults (40 pharmacological, 13 behavioural, one mixed intervention). Data for meta-analysis were available from 48 RCTs (n = 4052). Both pharmacological (mean difference (MD), -0.11mmol/L; 95% confidence interval (CI), [-0.19, -0.02], p = 0.02, n = 2536) and behavioural interventions (MD, -0.28mmol//L; 95% CI, [-0.43, -0.12], p<0.001, n = 956) were effective in lowering fasting glucose, but not HbA_1c (pharmacological MD, -0.03%; 95% CI, [-0.12, 0.06], p = 0.52, n = 1515; behavioural MD, 0.18%; 95% CI, [-0.07, 0.42], p = 0.16, n = 140) compared with usual care or placebo. In subgroup analysis of pharmacological interventions, metformin and antipsychotic switching strategies improved HbA_1c. Behavioural interventions of longer duration and those including repeated physical activity had greater effects on fasting glucose than those without these characteristics. Baseline levels of fasting glucose explained some of the heterogeneity in behavioural interventions but not in pharmacological interventions. Although the strength of the evidence is limited by inadequate trial design and reporting and significant heterogeneity, there is some evidence that behavioural interventions, antipsychotic switching, and metformin can lead to clinically important improvements in glycaemic measurements in adults with SMI.

Effects of Low Dose Metformin on Metabolic Traits in Clozapine-Treated Schizophrenia Patients: An Exploratory Twelve-Week Randomized, Double-Blind, Placebo-Controlled Study

Background

Metformin has been used for alleviating metabolic abnormalities in patients with schizophrenia. The lowest dose of metformin to treat metabolic abnormalities in clozapine-treated patients is 1000 mg/d. This study was designed to determine whether metformin at 500 mg/d and 1000 mg/d is effective in improving the metabolic profiles of clozapine-treated patients with pre-existing metabolic abnormalities, and whether its effectiveness depends on metformin dosage.

Methods

In this 12-week, randomized, double-blind, placebo-controlled trial, metformin at 500 mg/d or 1000 mg/d was prescribed to clozapine-treated patients with schizophrenia who had pre-existing metabolic abnormalities. The recruited patients underwent physical and laboratory evaluations at weeks 4, 8, and 12. The outcomes were any changes in metabolic traits.

Results

Among the 96 clozapine-treated patients with schizophrenia screened for the trial, 55 patients with pre-existing metabolic abnormalities were randomly assigned to placebo (n = 18), metformin dosage at 500 mg/d (n = 18), and metformin dosage at 1000 mg/d (n = 19) groups. The body weight (BW) of patients in the metformin 1000 mg/d group significantly decreased, by a mean of 0.97 kg over the 12 week trial period. Moreover, patients in the metformin at 500 mg/d and 1000 mg/d groups had a significant decrease in body mass index (BMI) after 12 weeks, with the mean decrease being 0.70 and 0.50 kg/m², respectively. No significant changes were observed in the other metabolic parameters of patients in the three groups.

Conclusions

Our results demonstrated that a low metformin dosage of either 500 mg/d or 1000 mg/d for 12 weeks slightly reduced the BW and BMI of clozapine-treated patients with pre-existing metabolic abnormalities. A longer period of treatment with a larger sample is warranted to determine the factors that influence the metformin treatment response.

Trial Registration

ClinicalTrials.gov NCT02751307

Metformin treatment of antipsychotic-induced dyslipidemia: an analysis of two randomized, placebo-controlled trials

Dyslipidemia is one of the most common adverse effects in schizophrenia patients treated with antipsychotics. However, there are no established effective treatments. In this study, data were pooled from two randomized, placebo-controlled trials, which were originally designed to examine the efficacy of metformin in treating antipsychotic-induced weight gain and other metabolic abnormalities. In total, 201 schizophrenia patients with dyslipidemia after being treated with an antipsychotic were assigned to take 1000 mg day^-1 metformin (n=103) or placebo (n=98) for 24 weeks, with evaluation at baseline, week 12 and week 24. The primary outcome was the low-density lipoprotein cholesterol (LDL-C) levels. After metformin treatment, the mean difference in the LDL-C value between metformin treatment and placebo was from 0.16 mmol l^-1 at baseline to -0.86 mmol l^-1 at the end of week 24, decreased by 1.02 mmol l^-1 (P<0.0001); and 25.3% of patients in the metformin group had LDL-C ≥3.37 mmol l^-1, which is significantly <64.8% in the placebo group (P<0.001) at week 24. Compared with the placebo, metformin treatment also have a significant effect on reducing weight, body mass index, insulin, insulin resistance index, total cholesterol and triglyceride, and increasing high-density lipoprotein cholesterol. The treatment effects on weight and insulin resistance appeared at week 12 and further improved at week 24, but the effects on improving dyslipidemia only significantly occurred at the end of week 24. We found that metformin treatment was effective in improving antipsychotic-induced dyslipidemia and insulin resistance, and the effects improving antipsychotic-induced insulin resistance appeared earlier than the reducing dyslipidemia.

Metformin in prevention and treatment of antipsychotic induced weight gain: a systematic review and meta-analysis

BACKGROUND

Most antipsychotics are associated with weight gain and other metabolic complications. Several randomized trials have shown metformin to be effective, but this still hasn't been included in clinical guidelines on managing antipsychotic induced weight gain.

METHODS

All double blind placebo controlled trials assessing the efficacy of metformin in the treatment of antipsychotic induced weight gain were included. Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE were searched for the period January 2000-December 2015. Meta-analysis was carried out using the random effects model.

RESULTS

Meta analysis of 12 published studies with a total of 743 patients found that in patients treated with antipsychotics, metformin treatment resulted in significantly better anthropometric and metabolic parameters than placebo. The mean change in weight was -3.27 kg (95 % CI -4.66 to -1.89) (Z = 4.64, p < 0.001). Metformin compared to placebo resulted in significant reduction in BMI [-1.13 kg/m2 (95 % CI -1.61 to -0.66)] and insulin resistance index [-1.49 (95 % CI -2.40 to -0.59)] but not fasting blood sugar [-2.48 mg/dl (95 % CI -5.54 to 0.57].

CONCLUSION

This meta-analysis confirms that metformin is effective in treating antipsychotic induced weight gain in patients with schizophrenia or schizoaffective disorder.

A systematic review and meta-analysis of randomised controlled trials of treatments for clozapine-induced obesity and metabolic syndrome

Metabolic complications are commonly found in people treated with clozapine. Reviews on the management of this problem have generally drawn conclusions by grouping different types of studies involving patients treated with various different antipsychotics. We carried out a systematic review and meta-analysis of pharmacological and non-pharmacological treatments for clozapine-induced obesity or metabolic syndrome. Two researchers independently searched PubMed and Embase for randomised controlled trials (RCTs) of treatments for clozapine-induced obesity or metabolic syndrome. All other types of studies were excluded. We only included RCTs where more than 50% of participants were taking clozapine. We identified 15 RCTs. Effective pharmacological treatments for clozapine-induced obesity and metabolic syndrome include metformin, aripiprazole, and Orlistat (in men only). Meta-analysis of three studies showed a robust effect of metformin in reducing body mass index and waist circumference but no effects on blood glucose, triglyceride levels, or HDL levels. In addition, there is limited evidence for combined calorie restriction and exercise as a non-pharmacological alternative for the treatment of clozapine-induced obesity, but only in an in-patient setting. Rosiglitazone, topiramate, sibutramine, phenylpropanolamine, modafinil, and atomoxetine have not shown to be beneficial, despite reports of efficacy in other populations treated with different antipsychotics. We conclude that randomised-controlled trial data support the use of metformin, aripiprazole, and Orlistat (in men only) for treating clozapine-induced obesity. Calorie restriction in combination with an exercise programme may be effective as a non-pharmacological alternative. Findings from trials in different populations should not be extrapolated to people being treated with clozapine.

A Guide to the Management of Clozapine-Related Tolerability and Safety Concerns

Clozapine is a highly effective antipsychotic medication, which provides a range of significant benefits for patients with schizophrenia, and is the standard of care for treatment-resistant schizophrenia as well as for reducing the risk of suicidal behaviors in schizophrenia and schizoaffective disorder. However, clozapine is widely underutilized, largely because prescribing clinicians lack experience in prescribing it and managing its adverse events (AEs). Clozapine is associated with 3 uncommon but immediately dangerous AEs, agranulocytosis, myocarditis/cardiomyopathy, and seizures, as well as AEs that may become dangerous if neglected, including weight gain, metabolic syndrome and constipation, and others that are annoying or distressing such as sedation, nighttime enuresis and hypersalivation. Because of the risk of agranulocytosis, clozapine formulations are available only through restricted distribution via a patient registry, with mandatory, systematized monitoring for absolute neutrophil count using a specific algorithm. We identified articles on managing clozapine-associated AEs by searching PubMed using appropriate keywords and search techniques for each topic. A review of the prevalence and clinical characteristics of clozapine-associated AEs shows that these risks can be managed efficiently and effectively. The absolute risks for both agranulocytosis and myocarditis/cardiomyopathy are low, diminish after the first 6 months, and are further reduced with appropriate monitoring. Weight gain/metabolic disorders and constipation, which develop more gradually, can be mitigated with regular monitoring and timely interventions. Sedation, hypersalivation, and enuresis are common but manageable with ameliorative measures and/or medications.

Metformin for Clozapine Associated Obesity: A Systematic Review and Meta-Analysis

BACKGROUND

Although clozapine is the gold-standard for treatment refractory schizophrenia, it has the worst metabolic profile of all antipsychotics. This is partly mediated by clozapine's impact on glucagon-like peptide (GLP-1). There is an absence of robust evidence for effective treatments for clozapine associated weight gain and metabolic syndrome. Metformin, with its role in increasing GLP-1 may aid weight loss among people on clozapine.

METHODS

We conducted a systematic-review and meta-analysis of metformin versus placebo for change in weight and metabolic syndrome for people on clozapine without diabetes mellitus. We searched the Cochrane Schizophrenia Group's trial register, Pubmed and Embase, as well as the following Chinese databases: the Chinese Biomedical Literature Service System and China Knowledge Resource Integrated Database. This was supplemented by hand searches of key papers.

RESULTS

Eight studies, of which three were from Chinese databases, with 478 participants were included. We found that metformin was superior to placebo in terms of weight loss (-3.12kg, 95%CI -4.88kg to -1.37kg) and BMI (-1.18kg/m2, 95%CI -1.76kg/m2 to -0.61kg/m2). Metformin significantly improved three of the five components of metabolic syndrome; waist circumference, fasting glucose and triglycerides. Sensitivity analysis on study quality and duration did not greatly impact results.

CONCLUSIONS

Metformin led to clinically meaningful weight loss among people on clozapine, and may reduce the rates of metabolic syndrome. Inclusion of metformin into the treatment protocols of people on clozapine, as tolerated, should be considered.

TRIAL REGISTRATION

PROSPERO registration number: CRD42015029723.

Metformin for treatment of clozapine-induced weight gain in adult patients with schizophrenia: a meta-analysis

BACKGROUND

Long-term use of clozapine for individuals with schizophrenia carries a high risk for developing metabolic abnormalities, especially clozapine-induced weight gain. Previous studies suggest that metformin can decrease clozapine-induced weight gain, but the sample sizes of most of these studies are relatively small.

METHODS

We identified randomized controlled trials (RCTs) published prior to December 15, 2015 about the use of metformin to treat clozapine-induced weight gain in adults with schizophrenia by searching several English-language and Chinese-language databases. Two independent researchers did the screening and data extraction. We used Revman 5.3 to conduct the meta-analyses, assessed the risk of bias (RoB), and assessed the strength of the evidence using the Cochrane Grades of Recommendation, Assessment, Development, and Evaluation (GRADE).

RESULTS

Six studies with a pooled sample of 207 treatment-group patients and 207 control-group patients were included -- three double-blind, placebo-controlled RCTs and three RCTs that did not use placebo controls and were not blinded. The meta-analysis found that compared to the control condition, patients receiving metformin experienced significantly greater reductions in body weight (mean difference [MD]=-2.89 kg, 95% CI: -4.20 to -1.59 kg) and body mass index (BMI) (MD=-0.81, 95% CI: -1.16 to -0.45), but there was no significant difference between the groups in the prevalence of side effects. Based on the GRADE scale, the strength of the evidence for the change in weight outcome was 'moderate' and that for the change in BMI outcome was 'high', but the strength of evidence about differences in side effects between groups was 'low' or 'very low'.

CONCLUSIONS

Adjunctive treatment with metformin appears to be effective for treating clozapine-induced weight gain and elevations in BMI in adult patients with schizophrenia. However, the quality of the evidence about the safety of this treatment is low, follow-up time in the available studies is relatively short, and half of the studies did not employ blinded assessment of outcome measures. Larger studies with placebo controls that follow patients for at least 24 weeks and that make blinded assessments of a range of relevant outcome measures (weight, BMI, blood lipids, insulin resistance, etc.) are needed to confirm these results.

A Naturalistic Randomized Placebo-Controlled Trial of Extended-Release Metformin to Prevent Weight Gain Associated With Olanzapine in a US Community-Dwelling Population

OBJECTIVE

This 24-week pilot study assessed the efficacy, tolerability, and safety of adjunctive metformin versus placebo for the prevention of olanzapine-associated weight gain in community-dwelling adult patients with schizophrenia, schizoaffective disorder, bipolar disorder, or major depression with psychotic features.

METHODS

In a double-blind study, 25 patients were randomly assigned to receive 24 weeks of either olanzapine plus metformin or olanzapine plus placebo. Metformin extended release was titrated to 2000 mg daily as tolerated. No other antipsychotics were allowed, whereas psychotropic medications including antidepressants and mood stabilizers were permitted. The primary outcome measures were change in body weight and homeostatic model assessment for insulin resistance from baseline to week 24.

RESULTS

The intent-to-treat population comprised patients who had 1 or more post-baseline visit. Mean change in body weight for the olanzapine plus metformin (O/M) group was 5.5 lb, which was less than the 12.8 lb gain for the olanzapine plus placebo (O/P) group (P < 0.05). Compared with O/P group who gained 7% of their body weight, patients in the O/M group gained 3% (P < 0.037). Body mass index change in the O/M group was 0.85 versus 2.02 in the O/P group (P < 0.045). There was a trend for a greater increase in baseline to end point homeostatic model assessment for insulin resistance and waist circumference in the O/P group versus the O/M group.

CONCLUSIONS

In this naturalistic sample of typical US community-dwelling patients, metformin was effective and well tolerated for the prevention of olanzapine-associated weight gain. Adjunctive metformin should be studied in a similar but larger population to determine its role in the prevention of olanzapine-associated weight gain.

Is Metabolic Syndrome On the Radar? Improving Real-Time Detection of Metabolic Syndrome and Physician Response by Computerized Scan of the Electronic Medical Record

OBJECTIVE

Metabolic syndrome is a common underdiagnosed condition among psychiatric patients exacerbated by second-generation antipsychotics, with the exception of aripiprazole and ziprasidone. This study evaluated the prescribing and treating behavior with regard to antipsychotics and metabolic syndrome of psychiatrists before and after implementation of a mandatory admission order set and electronic notification of results.

METHOD

Baseline data from 9,100 consecutive psychiatric admissions to a mental health hospital (July 2013-July 2014) were compared to postintervention data (July 2014-January 2015), which included 1,499 consecutive patient records. The intervention initiated standardized admission testing with electronic notification to psychiatrists when patients met metabolic syndrome criteria (according to Axis III of the DSM-IV). Charts were examined for inclusion of this diagnosis at discharge and for treatment changes.

RESULTS

At baseline, only 2.4% of patients (n = 214) were evaluated for metabolic syndrome. Of these, 34.5% (0.8% of the total sample) met metabolic syndrome criteria. Only 15 patients (0.16%) were comprehensively treated. No chart listed metabolic syndrome under Axis III of the DSM-IV. After the intervention, the diagnosis of patients meeting the criteria for metabolic syndrome increased from 0% to 29.3%. Less than 3% of patients were switched to drugs with a more benign metabolic profile. All patients who continued on second-generation antipsychotics had metabolic retesting. Thirty-eight experienced a significant and rapid increase in triglyceride levels after only 3 to 17 days.

CONCLUSIONS

Mandatory intake testing increases the number of patients evaluated for metabolic syndrome. Electronic alerts increase the inclusion of metabolic syndrome among discharge diagnoses but rarely affect prescribing practices.

Interventions to Address Medical Conditions and Health-Risk Behaviors Among Persons With Serious Mental Illness: A Comprehensive Review

People with serious mental illness (SMI) have mortality rates 2 to 3 times higher than the overall US population, largely due to cardiovascular disease. The prevalence of cardiovascular risk factors such as obesity and diabetes mellitus and other conditions, such as HIV/AIDS, is heightened in this group. Based on the recommendations of a National Institute of Mental Health stakeholder meeting, we conducted a comprehensive review examining the strength of the evidence surrounding interventions to address major medical conditions and health-risk behaviors among persons with SMI. Peer-reviewed studies were identified using 4 major research databases. Randomized controlled trials and observational studies testing interventions to address medical conditions and risk behaviors among persons with schizophrenia and bipolar disorder between January 2000 and June 2014 were included. Information was abstracted from each study by 2 trained reviewers, who also rated study quality using a standard tool. Following individual study review, the quality of the evidence (high, medium, low) and the effectiveness of various interventions were synthesized. 108 studies were included. The majority of studies examined interventions to address overweight/obesity (n = 80). The strength of the evidence was high for 4 interventions: metformin and behavioral interventions had beneficial effects on weight loss; and bupropion and varenicline reduced tobacco smoking. The strength of the evidence was low for most other interventions reviewed. Future studies should test long-term interventions to cardiovascular risk factors and health-risk behaviors. In addition, future research should study implementation strategies to effectively translate efficacious interventions into real-world settings.

Metformin for treatment of antipsychotic-induced weight gain in a South Asian population with schizophrenia or schizoaffective disorder: A double blind, randomized, placebo controlled study

BACKGROUND

Antipsychotic-induced weight gain causes serious health problems. We investigated the efficacy and safety of metformin in treating antipsychotic-induced weight gain in South Asian patients.

METHODS

Sixty six adult patients with schizophrenia or schizoaffective disorder treated, with atypical antipsychotics, and who had increased by more than 10% their pre treatment body weight, were randomly assigned to receive metformin or placebo in a double-blind study. Patients received usual treatment and metformin 500 mg or placebo twice daily for 24 weeks. The primary outcome measure was change in body weight from baseline to week 24. Linear mixed models were used in the analysis.

RESULTS

Mean change in body weight in the metformin group was -1.56 kg (95% CI=-3.06 to -0.05) and 1.0 kg (95% CI=0.03-1.97) in the placebo group. Between-group difference was 2.56 kg. At 24 weeks the between-group difference showed significant time-by-treatment interaction (F=3.23, p=0.004). Between-group difference in BMI showed significant time-by-treatment interaction (F=3.41 p=0.03). There was no significant difference in waist-hip ratio or fasting blood sugar.

CONCLUSIONS

Metformin is effective in reducing weight in South Asian patients with schizophrenia or schizoaffective disorder who had increased their body by more than 10% after treatment with atypical antipsychotics.

Metformin attenuates olanzapine-induced hepatic, but not peripheral insulin resistance

Antipsychotics (APs) are linked to diabetes, even without weight gain. Whether anti-diabetic drugs are efficacious in reversing the direct effects of APs on glucose pathways is largely undetermined. We tested two metformin (Met) doses to prevent impairments seen following a dose of olanzapine (Ola) (3 mg/kg); glucokinetics were measured using the hyperinsulinemic-euglycemic clamp (HIEC). Met (150 mg/kg; n=13, or 400 mg/kg; n=11) or vehicle (Veh) (n=11) was administered through gavage preceding an overnight fast, followed by a second dose prior to the HIEC. Eleven additional animals were gavaged with Veh and received a Veh injection during the HIEC (Veh/Veh); all others received Ola. Basal glucose was similar across treatment groups. The Met 400 group had significantly greater glucose appearance (Ra) in the basal period (i.e., before Ola, or hyperinsulinemia) vs other groups. During hyperinsulinemia, glucose infusion rate (GINF) to maintain euglycemia (reflective of whole-body insulin sensitivity) was higher in Veh/Veh vs other groups. Met 150/Ola animals demonstrated increased GINF relative to Veh/Ola during early time points of the HIEC. Glucose utilization during hyperinsulinemia, relative to basal conditions, was significantly higher in Veh/Veh vs other groups. The change in hepatic glucose production (HGP) from basal to hyperinsulinemia demonstrated significantly greater decreases in Veh/Veh and Met 150/Ola groups vs Veh/Ola. Given the increase in basal Ra with Met 400, we measured serum lactate (substrate for HGP), finding increased levels in Met 400 vs Veh and Met 150. In conclusion, Met attenuates hepatic insulin resistance observed with acute Ola administration, but fails to improve peripheral insulin resistance. Use of supra-therapeutic doses of Met may mask metabolic benefits by increasing lactate.

Metformin for Weight Gain and Metabolic Abnormalities Associated With Antipsychotic Treatment: Meta-Analysis of Randomized Placebo-Controlled Trials

This meta-analysis examined the effectiveness and safety of metformin to prevent or treat weight gain and metabolic abnormalities associated with antipsychotic drugs. We systematically searched in both English- and Chinese-language databases for metformin randomized controlled clinical trials (RCTs) using placebo in patients taking antipsychotics. Twenty-one RCTs (11 published in English and 10 in Chinese) involving 1547 subjects (778 on metformin, 769 on placebo) were included in this meta-analysis. Metformin was significantly superior to placebo (standard mean differences, -0.69 to -0.51; P = 0.01-0.0001) in the primary outcome measures (body weight, body mass index, fasting glucose, fasting insulin, triglycerides, and total cholesterol). Metformin was significantly superior to placebo in some secondary outcome measures but not in others. Significantly higher frequencies of nausea/vomiting and diarrhea were found in the metformin group, but no differences were found in other adverse drug reactions. In the metformin group, the frequency of nausea/vomiting was 14%, and of diarrhea, 7%. Subgroup and sensitivity analyses demonstrated that primary outcomes were influenced by ethnicity, treatment style (intervention vs prevention), metformin dose, study duration, and mean age. Body weight standard mean difference was -0.91 (confidence interval [CI], -1.40 to -0.41) in 3 prevention RCTs in naive patients, -0.66 (CI, -1.02 to -0.30) in 5 intervention RCTs during the first year, and -0.50 (CI, -0.73 to -0.27) in 9 intervention RCTs in chronic patients. This meta-analysis suggests that adjunctive metformin is an effective, safe, and reasonable choice for antipsychotic-induced weight gain and metabolic abnormalities.

Therapeutic Use of Metformin in Prediabetes and Diabetes Prevention

People with elevated, non-diabetic, levels of blood glucose are at risk of progressing to clinical type 2 diabetes and are commonly termed 'prediabetic'. The term prediabetes usually refers to high-normal fasting plasma glucose (impaired fasting glucose) and/or plasma glucose 2 h following a 75 g oral glucose tolerance test (impaired glucose tolerance). Current US guidelines consider high-normal HbA1c to also represent a prediabetic state. Individuals with prediabetic levels of dysglycaemia are already at elevated risk of damage to the microvasculature and macrovasculature, resembling the long-term complications of diabetes. Halting or reversing the progressive decline in insulin sensitivity and β-cell function holds the key to achieving prevention of type 2 diabetes in at-risk subjects. Lifestyle interventions aimed at inducing weight loss, pharmacologic treatments (metformin, thiazolidinediones, acarbose, basal insulin and drugs for weight loss) and bariatric surgery have all been shown to reduce the risk of progression to type 2 diabetes in prediabetic subjects. However, lifestyle interventions are difficult for patients to maintain and the weight loss achieved tends to be regained over time. Metformin enhances the action of insulin in liver and skeletal muscle, and its efficacy for delaying or preventing the onset of diabetes has been proven in large, well-designed, randomised trials, such as the Diabetes Prevention Program and other studies. Decades of clinical use have demonstrated that metformin is generally well-tolerated and safe. We have reviewed in detail the evidence base supporting the therapeutic use of metformin for diabetes prevention.

Treatment of clozapine-associated obesity and diabetes with exenatide (CODEX) in adults with schizophrenia: study protocol for a pilot randomised controlled trial

BACKGROUND

Clozapine causes significant metabolic disturbances including obesity and type 2 diabetes. Recent evidence that reduced glucagon-like-peptide-1 (GLP-1) may contribute to aetiology of clozapine-associated metabolic dysregulation suggests a potential therapeutic role for GLP-1 agonists.

METHOD

This open-label, pilot randomised controlled trial evaluates the effect of exenatide in clozapine-treated obese adults who have schizophrenia, with or without poorly controlled diabetes. Sixty out-patients will be randomised to once weekly extended release exenatide or treatment as usual for 24 weeks.

AIMS

To evaluate the feasibility of larger studies regarding methodology, acceptability, tolerability and estimate efficacy for glycaemic control or weight loss. Secondary outcomes are psychosis severity and metabolic parameters.

CONCLUSIONS

This is the first trial investigating GLP-1 agonists for glycaemic control and weight loss in clozapine-treated patients with either diabetes or obesity. Clozapine-associated obesity and diabetes with exenatide (CODEX) will provide proof-of-concept empirical evidence addressing whether this novel treatment is practical and worthy of further investigation.

DECLARATION OF INTEREST

A.W.R. has received speaker honoraria and travel grants from AstraZeneca, BoehringerIngelheim, Eli Lilly, MSD, Novo Nordisk and Sanofi and has participated on advisory panels for MSD and Novo Nordisk.

COPYRIGHT AND USAGE

© The Royal College of Psychiatrists 2015. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.

Treatment of clozapine-associated weight gain: a systematic review

PURPOSE

Clozapine is an antipsychotic drug with superior efficacy in treatment-resistant schizophrenia. Clozapine is associated with a low likelihood of extrapyramidal symptoms and other neurological side-effects but a high propensity to induce weight gain and general metabolic dysregulation. Various pharmacological and behavioral treatment approaches for reducing clozapine-associated weight gain exist in the literature; however, there are currently no clear clinical guidelines as to which method is preferred. The aim of the current review is to systematically summarize studies that have studied both pharmacological and non-pharmacological interventions to attenuate or reverse clozapine-associated weight gain.

METHODS

A systematic review of EMBASE and MEDLINE databases of all articles published prior to January 2014 was conducted. Seventeen studies were identified as meeting inclusion criteria and included in the review.

RESULTS

Aripiprazole, fluvoxamine, metformin, and topiramate appear to be beneficial; however, available data are limited to between one and three randomized controlled trials per intervention. Orlistat shows beneficial effects, but in males only. Behavioral and nutritional interventions also show modest effects on decreasing clozapine-associated weight gain, although only a small number of such studies exist.

CONCLUSIONS

While a number of pharmacological interventions can produce modest weight loss, each may be associated with negative side effects, which should be considered before beginning treatment. Given the pressing need to improve cardiometabolic health in most clozapine-treated patients, substantially more research is needed to develop sound clinical practice guidelines for the treatment of clozapine-associated weight gain.

An overview of diabetes management in schizophrenia patients: office based strategies for primary care practitioners and endocrinologists

Diabetes is common and seen in one in five patients with schizophrenia. It is more prevalent than in the general population and contributes to the increased morbidity and shortened lifespan seen in this population. However, screening and treatment for diabetes and other metabolic conditions remain poor for these patients. Multiple factors including genetic risk, neurobiologic mechanisms, psychotropic medications, and environmental factors contribute to the increased prevalence of diabetes. Primary care physicians should be aware of adverse effects of psychotropic medications that can cause or exacerbate diabetes and its complications. Management of diabetes requires physicians to tailor treatment recommendations to address special needs of this population. In addition to behavioral interventions, medications such as metformin have shown promise in attenuating weight loss and preventing hyperglycemia in those patients being treated with antipsychotic medications. Targeted diabetes prevention and treatment is critical in patients with schizophrenia and evidence-based interventions should be considered early in the course of treatment. This paper reviews the prevalence, etiology, and treatment of diabetes in schizophrenia and outlines office based interventions for physicians treating this vulnerable population.

Pharmacological strategies to counteract antipsychotic-induced weight gain and metabolic adverse effects in schizophrenia: a systematic review and meta-analysis

BACKGROUND

Antipsychotic-induced metabolic adversities are often difficult to manage. Using concomitant medications to counteract these adversities may be a rational option.

OBJECTIVE

To systematically determine the effectiveness of medications to counteract antipsychotic-induced metabolic adversities in patients with schizophrenia.

DATA SOURCES

Published articles until November 2013 were searched using 5 electronic databases. Clinical trial registries were searched for unpublished trials.

STUDY SELECTION

Double-blind randomized placebo-controlled trials focusing on patients with schizophrenia were included if they evaluated the effects of concomitant medications on antipsychotic-induced metabolic adversities as a primary outcome.

DATA EXTRACTION

Variables relating to participants, interventions, comparisons, outcomes, and study design were extracted. The primary outcome was change in body weight. Secondary outcomes included clinically relevant weight change, fasting glucose, hemoglobin A1c, fasting insulin, insulin resistance, cholesterol, and triglycerides.

DATA SYNTHESIS

Forty trials representing 19 unique interventions were included in this meta-analysis. Metformin was the most extensively studied drug in regard to body weight, the mean difference amounting to -3.17 kg (95% CI: -4.44 to -1.90 kg) compared to placebo. Pooled effects for topiramate, sibutramine, aripiprazole, and reboxetine were also different from placebo. Furthermore, metformin and rosiglitazone improved insulin resistance, while aripiprazole, metformin, and sibutramine decreased blood lipids.

CONCLUSION

When nonpharmacological strategies alone are insufficient, and switching antipsychotics to relatively weight-neutral agents is not feasible, the literature supports the use of concomitant metformin as first choice among pharmacological interventions to counteract antipsychotic-induced weight gain and other metabolic adversities in schizophrenia.

Diazepam potentiates the antidiabetic, antistress and anxiolytic activities of metformin in type-2 diabetes mellitus with cooccurring stress in experimental animals

Psychological stress is considered as one of the limiting factors in the management of type-2 diabetes mellitus (T2DM). Therefore, the basic objective of the present study was to evaluate the antidiabetic effect of metformin, diazepam, and their combination in cooccurring T2DM and stress condition (DMS). T2DM was induced in the male rats by administering streptozotocin (45 mg/kg, i.p.) and nicotinamide (110 mg/kg, i.p.) with time lag of 15 min. Rats were subjected to two sessions of cold restraint stress paradigm for one hour on the sixth and seventh day after streptozotocin injection. Administration of metformin (25 mg/kg, p.o.) and diazepam (1 mg/kg, p.o.) in combination from the seventh to thirteenth day after streptozotocin injection showed better improvement in glucose tolerance and insulin sensitivity compared to monotherapy of either drug. In addition, the combination significantly attenuated DMS-induced hyperglycemia, hypertriglyceridaemia, hypercorticosteronemia, anxiety-like behavior, and insulin resistance through modulating insulin signaling pathway in the liver compared to monotherapy. Further, improvement of mitochondrial function, integrity, and oxidative stress in hippocampus, hypothalamus, prefrontal cortex, striatum, amygdala, and nucleus accumbens was observed with the combination. Therefore, metformin in combination with diazepam may be a better therapeutic option in the management of T2DM with cooccurring stress condition.

Antidiabetic-drug combination treatment for glucose intolerance in adult female rats treated acutely with olanzapine

Second generation antipsychotic drugs are routinely used as treatment for psychotic disorders. Many of these compounds, including olanzapine, cause metabolic side-effects such as impaired glucose tolerance and insulin resistance. Individual antidiabetic drugs can help control elevated glucose levels in patients treated with antipsychotics, but the effects of combining antidiabetics, which routinely occurs with Type 2 diabetes mellitus patients, have never been studied. Presently, we compared the effects of the three different antidiabetics metformin (500mg/kg, p.o.), rosiglitazone (30mg/kg, p.o.) and glyburide (10mg/kg, p.o.) on metabolic dysregulation in adult female rats treated acutely with olanzapine. In addition, dual combinations of each of these antidiabetics were compared head-to-head against each other and the individual drugs. The animals received two daily treatments with antidiabetics and were then treated acutely with olanzapine (10mg/kg, i.p.). Fasting glucose and insulin levels were measured, followed by a 2h glucose tolerance test. Olanzapine caused a large and highly significant glucose intolerance compared to vehicle treated rats. Rosiglitazone decreased glucose levels non-significantly, while both metformin and glyburide significantly decreased glucose levels compared to olanzapine-only treated animals. For antidiabetic dual-drug combinations, the rosiglitazone-metformin group showed an unexpected increase in glucose levels compared to all of the single antidiabetic drugs. However, both the metformin-glyburide and rosiglitazone-glyburide groups showed significantly greater reductions in glucose levels following olanzapine than with single drug treatment alone for metformin or rosiglitazone, bringing glucose levels down to values equivalent to vehicle-only treated animals. These findings indicate that further study of antidiabetic dual-drug combinations in patients treated with antipsychotic drugs is warranted.

Metformin for weight loss and metabolic control in overweight outpatients with schizophrenia and schizoaffective disorder

OBJECTIVE

The purpose of this study was to determine whether metformin promotes weight loss in overweight outpatients with chronic schizophrenia or schizoaffective disorder.

METHOD

In a double-blind study, 148 clinically stable, overweight (body mass index [BMI] ≥27) outpatients with chronic schizophrenia or schizoaffective disorder were randomly assigned to receive 16 weeks of metformin or placebo. Metformin was titrated up to 1,000 mg twice daily, as tolerated. All patients continued to receive their prestudy medications, and all received weekly diet and exercise counseling. The primary outcome measure was change in body weight from baseline to week 16.

RESULTS

Fifty-eight (77.3%) patients who received metformin and 58 (81.7%) who received placebo completed 16 weeks of treatment. Mean change in body weight was -3.0 kg (95% CI=-4.0 to -2.0) for the metformin group and -1.0 kg (95% CI=-2.0 to 0.0) for the placebo group, with a between-group difference of -2.0 kg (95% CI=-3.4 to -0.6). Metformin also demonstrated a significant between-group advantage for BMI (-0.7; 95% CI=-1.1 to -0.2), triglyceride level (-20.2 mg/dL; 95% CI=-39.2 to -1.3), and hemoglobin A1c level (-0.07%; 95% CI=-0.14 to -0.004). Metformin-associated side effects were mostly gastrointestinal and generally transient, and they rarely led to treatment discontinuation.

CONCLUSIONS

Metformin was modestly effective in reducing weight and other risk factors for cardiovascular disease in clinically stable, overweight outpatients with chronic schizophrenia or schizoaffective disorder over 16 weeks. A significant time-by-treatment interaction suggests that benefits of metformin may continue to accrue with longer treatment. Metformin may have an important role in diminishing the adverse consequences of obesity and metabolic impairments in patients with schizophrenia.

Metabolic side-effects of the novel second-generation antipsychotic drugs asenapine and iloperidone: a comparison with olanzapine

Background

The second generation antipsychotic (SGA) drugs are widely used in psychiatry due to their clinical efficacy and low incidence of neurological side-effects. However, many drugs in this class cause deleterious metabolic side-effects. Animal models accurately predict metabolic side-effects for SGAs with known clinical metabolic liability. We therefore used preclinical models to evaluate the metabolic side-effects of glucose intolerance and insulin resistance with the novel SGAs asenapine and iloperidone for the first time. Olanzapine was used as a comparator.

Methods

Adults female rats were treated with asenapine (0.01, 0.05, 0.1, 0.5, 1.0 mg/kg), iloperidone (0.03, 0.5, 1.0, 5.0, 10.0 mg/kg) or olanzapine (0.1, 0.5, 1.5, 5.0, 10.0 mg/kg) and subjected to the glucose tolerance test (GTT). Separate groups of rats were treated with asenapine (0.1 and 1.0 mg/kg), iloperidone (1.0 and 10 mg/kg) or olanzapine (1.5 and 15 mg/kg) and tested for insulin resistance with the hyperinsulinemic-euglycemic clamp (HIEC).

Results

Asenapine showed no metabolic effects at any dose in either test. Iloperidone caused large and significant glucose intolerance with the three highest doses in the GTT, and insulin resistance with both doses in the HIEC. Olanzapine caused significant glucose intolerance with the three highest doses in the GTT, and insulin resistance with the higher dose in the HIEC.

Conclusions

In preclinical models, asenapine shows negligible metabolic liability. By contrast, iloperidone exhibits substantial metabolic liability, comparable to olanzapine. These results emphasize the need for appropriate metabolic testing in patients treated with novel SGAs where current clinical data do not exist.

Clozapine: balancing safety with superior antipsychotic efficacy

Clozapine is often referred to as the gold standard for the treatment of schizophrenia and yet has also been described as the most underutilized treatment for schizophrenia supported by solid evidence-based medicine. In 2008, it was used to treat only 4.4% of patients with schizophrenia in the U.S., which is ~10-20% of those with approved indications for clozapine for which there is no alternative of equal efficacy. Its use is much higher in Scandinavian countries and China. The primary indications for clozapine are: 1) treatment-resistant schizophrenia or schizoaffective disorder, defined as persistent moderate to severe delusions or hallucinations despite two or more clinical trials with other antipsychotic drugs; and, 2) patients with schizophrenia or schizoaffective disorder who are at high risk for suicide. Concerns over a number of safety considerations are responsible for much of the underutilization of clozapine: 1) agranulocytosis; 2) metabolic side effects; and, 3) myocarditis. These side effects can be detected, prevented, minimized and treated, but there will be a very small number of fatalities. Nevertheless, clozapine has been found in two large epidemiologic studies to have the lowest mortality of any antipsychotic drug, mainly due to its very large effect to reduce the risk for suicide. Other reasons for limited use of clozapine include the extra effort entailed in monitoring white blood cell counts to detect granulocytopenia or agranulocytosis and, possibly, minimal efforts to market it now that it is largely generic. Awareness of the benefits and risks of clozapine is essential for increasing the use of this lifesaving agent.

Interventions for the metabolic syndrome in schizophrenia: a review

The metabolic syndrome (MetS) is an increasingly prevalent condition in people with schizophrenia. It remains highly prevalent in the general population in developed countries, but recently health promotion campaigns and greater awareness of the high associated mortality rates have resulted in improvements in the rates of cardiovascular risk factors. This is not the case for people with schizophrenia who continue to have more than twice the rates of MetS and significantly higher mortality rates than the general population. Various behavioural and pharmacological interventions have been used to improve conditions that are linked to MetS, mainly smoking and obesity. This review aims to provide an update of the latest knowledge about the behavioural, pharmacological and other interventions that might help to combat this life-threatening problem in people with schizophrenia.