Antipsychotic-Induced Weight Gain in Severe Mental Illness: Risk Factors and Special Considerations

PURPOSE OF REVIEW

Weight gain is a disconcerting issue experienced by patients treated with antipsychotics (APs). This review summarizes current knowledge on the prevalence, etiology, and risk factors for antipsychotic-induced weight gain (AIWG), and evidence for interventions, including special considerations.

RECENT FINDINGS

Predisposing risk factors for AIWG include lack of prior AP exposure, sex, and age. AP dose and duration of exposure are additional treatment-related factors that may contribute to this issue. Among current approaches to target AIWG, metformin has the most evidence to support its use, and this is increasingly reflected in clinical guidelines. While lifestyle approaches are recommended, cost-effectiveness and scalability represent limitations. More research is needed to identify newer treatment options and inform clinical recommendations for AIWG. Concerns around scope of practice in psychiatry to address AIWG and related comorbidities will require enhanced training opportunities and interdisciplinary collaborations, as well as updated position statements/practice guidelines emphasizing prevention.

Long-term treatment of antipsychotics and combined therapy with other psychotropic medications inducing weight gain in patients with non-affective psychotic disorder: Evidence from GROUP, a longitudinal study

INTRODUCTION

Antipsychotics (APs) can cause weight gain. Little is known about changes in weight when APs are combined with other psychotropics. This study examines the weight change in patients undergoing long-term treatment with APs or with AP combined with other psychotropics.

METHODS

Patients with non-affective psychotic disorder from the GROUP study were divided into three groups: AP medication group (APm) (n = 100), AP in combination with other psychotropics (APc) (n = 73), and medication-free (Meds-free) (n = 100). Weight change was examined at inclusion and after three years using a paired-sample t-test. An Independent-sample t-test was performed to evaluate weight change among patients taking clozapine, olanzapine, and quetiapine and individuals not taking these medications. Linear regression was performed to evaluate the association between covariates and weight.

RESULTS

Patients in the APm group [mean = 1.800 kg, t(99)=2.849, 95% CI(0.546, 3.054), p = 0.005] and the APc group [mean = 1.877 kg, t(72)=2.688, 95% CI(0.485, 3.268), p = 0.009] showed significant weight gain. Patients taking clozapine, olanzapine or quetiapine showed significant weight gain compared to those not taking these medications [mean difference=1.707 kg, t(271)= 2.061, 95% CI(0.077, 3.337), p = 0.040)].

CONCLUSION

Patients receiving APs and APs with other psychotropics gain weight during long-term treatment. It is possible that weight gain is mainly driven by APs.

Metabolic disturbances associated with antipsychotic drug treatment in patients with schizophrenia: State-of-the-art and future perspectives

Metabolic disturbances and obesity are major cardiovascular risk factors in patients with schizophrenia, resulting in a higher mortality rate and shorter life expectancy compared with those in the general population. Although schizophrenia and metabolic disturbances may share certain genetic or pathobiological risks, antipsychotics, particularly those of second generation, may further increase the risk of weight gain and metabolic disturbances in patients with schizophrenia. This review included articles on weight gain and metabolic disturbances related to antipsychotics and their mechanisms, monitoring guidelines, and interventions. Nearly all antipsychotics are associated with weight gain, but the degree of the weight gain varies considerably. Although certain neurotransmitter receptor-binding affinities and hormones are correlated with weight gain and specific metabolic abnormalities, the precise mechanisms underlying antipsychotic-induced weight gain and metabolic disturbances remain unclear. Emerging evidence indicates the role of genetic polymorphisms associated with antipsychotic-induced weight gain and antipsychotic-induced metabolic disturbances. Although many guidelines for screening and monitoring antipsychotic-induced metabolic disturbances have been developed, they are not routinely implemented in clinical care. Numerous studies have also investigated strategies for managing antipsychotic-induced metabolic disturbances. Thus, patients and their caregivers must be educated and motivated to pursue a healthier life through smoking cessation and dietary and physical activity programs. If lifestyle intervention fails, switching to another antipsychotic drug with a lower metabolic risk or adding adjunctive medication to mitigate weight gain should be considered. Antipsychotic medications are essential for schizophrenia treatment, hence clinicians should monitor and manage the resulting weight gain and metabolic disturbances.

The Effects of folic acid and topiramate on peripheral nerve regeneration

Peripheral nerve injury creates unusual sensitivity and pathological spontaneous activity in neurons that are described as ectopic discharge. Voltage dependent Na channels are responsible for ectopic discharge. Topiramate (TOP) inhibits voltage-gated sodium channels by blocking both the amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate receptor and folic acid (FA) activity in neurotransmitter synthesis reactions. FA and TOP are anti-apoptotic agents by both phosphorylated-Akt (p-Akt) signaling activation and anti-inflammatory effects at the injury site. We investigated the effects of FA and TOP in peripheral nerve injury. We used rats with a sciatic nerve injury (SNI) treated with FA or TOP once daily for 6 weeks. Histological and electrophysiological tests were used to evaluate the morphology, and motor and sensory functions. Numbers of axons, myelin sheath thickness and axon area were measured using stereological techniques; functionality also was evaluated. Although FA exhibited a positive effect on regeneration by increasing the number of axons, we found no difference in axonal outgrowth or myelin sheath formation between the TOP and FA groups.

Topical Topiramate Improves Wound Healing in an Animal Model of Hyperglycemia

Wound healing is severely affected in hyperglycemia and other metabolic conditions. Finding new therapeutic approaches that accelerate wound healing and improve the quality of the scar may reduce the morbidity commonly associated with skin lesions in diabetes. This study evaluated the effect of topical topiramate (TPM) on wound healing in C57 mice. Streptozotocin-induced hyperglycemic mice were subjected to a wound on the back and randomly allocated for treatment with either vehicle or topical TPM cream (2%) once a day for 14 days. Polymerase chain reaction, Western blotting, and microscopy were performed for the analysis. TPM improved wound healing (complete resolution at Day 10, 98% ± 5 for TPM vs. 81% ± 28 for vehicle), increased organization and deposition of collagen Type I, and enhanced the quality of the scars as determined by microscopy. In addition, TPM modulated the expression of cytokines and proteins of the insulin-signaling pathway: In early wound-healing stages, expression of interleukin-10, an anti-inflammatory marker, increased, whereas at the late phase, the pro-inflammatory markers tumor necrosis factor-α and monocyte chemoattractant protein-1 increased and there was increased expression of a vascular endothelial growth factor. Proteins of the insulin-signaling pathway were stimulated in the late wound-healing phase. Topical TPM improves the quality of wound healing in an animal model of hyperglycemia. The effect of TPM is accompanied by modulation of inflammatory and growth factors and proteins of the insulin-signaling pathway. Therefore, topical TPM presents as a potential therapeutic agent in skin wounds in patients with hyperglycemia.

Antipsychotics and glucose metabolism: how brain and body collide

Since the serendipitous discovery of the first antipsychotic (AP) drug in the 1950s, APs remain the cornerstone of treatment for schizophrenia. A shift over the past two decades away from first-generation, conventional APs to so-called "atypical" (or 2nd/3rd generation) APs parallels acknowledgment of serious metabolic side-effects associated in particular with these newer agents. As will be reviewed, AP drugs and type 2 diabetes are now inextricably linked, contributing to the three- to fivefold increased risk of type 2 diabetes observed in schizophrenia. However, this association is not straightforward. Biological and lifestyle-related illness factors contribute to the association between type 2 diabetes and metabolic disease independently of AP treatment. In addition, APs have a well-established weight gain propensity which could also account for elevated risk of insulin resistance and type 2 diabetes. However, compelling preclinical and clinical evidence now suggests that these drugs can rapidly and directly influence pathways of glucose metabolism independently of weight gain and even in absence of psychiatric illness. Mechanisms of these direct effects remain poorly elucidated but may involve central and peripheral antagonism of neurotransmitters implicated not only in the therapeutic effects of APs but also in glucose homeostasis, possibly via effects on the autonomic nervous system. The clinical relevance of studying "direct" effects of these drugs on glucose metabolism is underscored by the widespread use of these medications, both on and off label, for a growing number of mental illnesses, extending safety concerns well beyond schizophrenia.

Topiramate's effectiveness on weight reduction in overweight/obese persons with schizophrenia: study protocol for a randomized controlled trial

BACKGROUND

Schizophrenia is a psychiatric disorder with a higher mortality than that of the general population. Most of the deaths are due to cardiovascular causes and are related to metabolic risks. This risk is due not only to antipsychotics but also to inherent factors of the disorder. Studies in the West have shown topiramate to be effective in schizophrenia to reduce weight gain and for symptomatic control. Whether this is effective for South Asians is not known. It is important because South Asians have a higher risk of metabolic syndrome. We aim to conduct a double-blind, randomized controlled trial comparing topiramate add-on therapy with treatment as usual with antipsychotics in patients with schizophrenia in an outpatient setting in Sri Lanka.

METHODS/DESIGN

Ninety patients with schizophrenia presenting to the Colombo North Teaching Hospital will be randomized to intervention and control groups equally using permuted block randomization. Patients with comorbid metabolic disorders and taking prescribed weight-controlling medications will be excluded. The intervention group will be prescribed topiramate in addition to their antipsychotics in a predefined dosing regimen targeting a dose of 100 mg per day. The control subjects are to receive a placebo. As the primary outcome, anthropometric measurements including weight, waist circumference, skinfold thickness, and body mass index will be recorded at baseline and monthly during the study period of 3 months. The secondary outcome is the change in symptoms according to the clinician-administered Brief Psychiatric Rating Scale. Assessment of capacity will be performed and informed consent obtained from all subjects. Ethics approval has been obtained from the ethical review committee of the Faculty of Medicine, University of Kelaniya, and the trial has been registered in the Sri Lanka Clinical Trials Registry.

DISCUSSION

In this double-blind, randomized controlled trial, we will attempt to assess the effectiveness of topiramate as an add-on therapy compared with treatment as usual for weight control in patients with schizophrenia. To our knowledge, this is the first such study in South Asia, where metabolic risks are found to be higher than in the West and could have unique ethnic factors related to weight gain in schizophrenia.

TRIAL REGISTRATION

Sri Lanka Clinical Trials Registry, SLCTR/2017/003 . Registered on 20 February 2017. Universal trial number, U1111-1192-9439.

Prevalence of Metabolic Syndrome in Patients with Schizophrenia in Korea: A Multicenter Nationwide Cross-Sectional Study

OBJECTIVE

We designed a nationwide study with limited exclusion criteria to investigate the prevalence of metabolic syndrome (MetS) in Korea and its relationship with antipsychotic medications.

METHODS

This multicenter, cross-sectional, and observational study included patients diagnosed with schizophrenia or schizoaffective disorder. Sixteen hospitals enrolled 845 patients aged 18 to 65 years prescribed any antipsychotic medication between August 2011 and August 2013. MetS was diagnosed using the criteria of the modified Adult Treatment Panel III of the National Cholesterol Education Program with the Korean abdominal obesity definition (waist circumference ≥85 cm in women, ≥90 cm in men).

RESULTS

The prevalence of MetS in all patients was 36.5% and was significantly higher in men than women (men, 40.8%; women, 32.2%) and was significantly correlated with age [odds ratio (OR) 1.02] and duration of illness (OR 1.03). The prevalence of MetS across antipsychotic drugs in the major monotherapy group was as follows: 18.8% for quetiapine, 22.0% for aripiprazole, 33.3% for both amisulpride and paliperidone, 34.0% for olanzapine, 35% for risperidone, 39.4% for haloperidol, and 44.7% for clozapine.

CONCLUSION

The prevalence of MetS is very high in patients with schizophrenia or schizoaffective disorder. Screening and monitoring of MetS is also strongly recommended.

Efficacy and safety of adjunctive topiramate for schizophrenia: a meta-analysis of randomized controlled trials

OBJECTIVE

To systematically examine the randomized controlled trial (RCT) evidence regarding efficacy and tolerability of topiramate cotreatment with antipsychotics in schizophrenia-spectrum disorders.

METHODS

Random-effects meta-analysis of RCTs of topiramate cotreatment with antipsychotics vs. placebo/ongoing antipsychotic treatment in schizophrenia-spectrum disorders. Standardized or weighted mean difference (SMD/WMD), risk ratio (RR) ±95% confidence intervals (CIs), and number needed to harm (NNH) were calculated.

RESULTS

Across 16 RCTs (n = 934, duration = 11.8 ± 5.6 weeks), topiramate outperformed the comparator regarding change/endpoint of total (SMD: -0.58, 95% CI: -0.82, -0.35, P < 0.00001), positive (SMD: -0.37, 95% CI: -0.61, -0.14, P = 0.002), negative (SMD: -0.58, 95% CI: -0.87, -0.29, P < 0.0001), and general symptoms (SMD: -0.68, 95% CI: -0.95, -0.40, P < 0.00001). Furthermore, topiramate was superior regarding body weight (WMD: -2.75 kg, 95% CI: -4.03, -1.47, P < 0.0001), body mass index (BMI) (WMD: -1.77, 95% CI: -2.38, -1.15, P < 0.00001), triglycerides (P = 0.006), and insulin levels (P < 0.00001). Superiority regarding psychopathology and body weight/BMI was consistent across Chinese/Asian and Western RCTs, double-blind and open designs, clozapine and non-clozapine cotreatment, augmentation and co-initiation RCTs, and higher and lower quality RCTs. In meta-regression analyses, topiramate's efficacy for total symptoms was moderated by shorter illness duration (P = 0.047), while weight loss was greater in prevention/co-initiation vs. intervention/augmentation RCTs (-4.11 kg, 95% CI: -6.70, -1.52 vs. -1.41 kg, 95% CI: -2.23, -0.59, P < 0.001). All-cause discontinuation was similar between topiramate and comparators (RR: 1.28, 95% CI: 0.91, 1.81, P = 0.16). While topiramate led to more concentration/attention difficulties (P = 0.03, NNH = 8, 95% CI=4-25), psychomotor slowing (P = 0.02, NNH = 7, 95% CI = 4-25), and paresthesia (P = 0.05, NNH = 2, 95% CI = 4-33), it led to less ≥7% weight gain (P = 0.0001, NNH = 2, 95% CI = 2-3) and constipation (P = 0.04, NNH = 9, 95% CI = 5-100) than the comparator.

CONCLUSIONS

These results indicate that adjunctive topiramate to antipsychotics is an effective and safe treatment choice for symptomatic improvement and weight reduction in patients with schizophrenia-spectrum disorders.

Efficacy and tolerability of topiramate-augmentation therapy for schizophrenia: a systematic review and meta-analysis of randomized controlled trials

This study aimed to perform a comprehensive meta-analysis of topiramate-augmentation therapy in patients with schizophrenia receiving antipsychotic agents. Data published up to June 20, 2016 were obtained from the PubMed, PsycINFO, and Cochrane Library databases. Twelve randomized controlled trials comparing topiramate to placebo or antipsychotic only were included (n=676 patients). The primary outcome was change in overall symptoms. Relative risk (RR) and standardized mean difference (SMD), along with 95% confidence intervals, were calculated using random effects model for each outcome. Topiramate-augmentation therapy was superior to the control for decreasing overall symptoms (SMD -0.55, 95% confidence interval -0.86 to -0.24; P=0.001; I²=55%, eight comparisons, n=380), positive symptoms (SMD -0.4), negative symptoms (SMD -0.47), and Positive and Negative Syndrome Scale general subscale scores (SMD -0.67). Furthermore, topiramate-augmentation therapy decreased weight (SMD -0.69) and body mass index (SMD -0.95) compared with the control. Topiramate was similar to the control with respect to discontinuation due to all causes (RR 1.19), inefficacy (RR 1.71), and adverse events (RR 1.09). Topiramate was associated with higher incidence of paresthesia (RR 2.67) and attention difficulty (RR 8.97) compared with the control. Our results seemed to suggest that topiramate-augmentation therapy improves the psychopathology of schizophrenia with good tolerability and has the additional advantage of weight maintenance. However, because there were some limitations (numbers of studies and patients included in the meta-analysis were small, some studies used completer analysis, Chinese studies were included in the meta-analysis, and studies that had a risk of bias were included in the meta-analysis) in this study, we cannot apply the results of this study in daily clinical practice.

Glutamatergic agents for schizophrenia: current evidence and perspectives

Suboptimal outcomes in schizophrenia are a consequence of lacking insight into the etiology, biomarkers and treatment-relevant subgroups, the therapeutic restriction to dopaminergic-modulating antipsychotics that fail to significantly improve negative and cognitive symptoms, non-adherence, and, in the case of treatment-resistance, the underutilization of clozapine. Evidence suggests additional, extra-dopaminergic abnormalities in amino acid neurotransmission, particularly the glutamatergic system. Antidopaminergic antipsychotics modulate this system on several levels, as do mood stabilizers, including lamotrigine, topiramate and pregabaline. Recently, agonists at metabotropic glutamate receptors and glycine uptake inhibitors failed in large placebo-controlled trials for schizophrenia. Problems to overcome for successfully leveraging glutamatergic agents for schizophrenia are patient selection, focus on positive symptoms and late disease stages, and dose-response relationships. Because glutamate guides processes of brain development and maturation, clinical research should focus on the at-risk mental state or first-episode psychosis, address cognition and negative symptoms and use monotherapy designs in parallel to augmentation strategies.

New therapeutic approaches for treatment-resistant schizophrenia: a look to the future

Schizophrenia for many patients is a lifelong mental disorder with significant consequences on most functional domains. One fifth to one third of patients with schizophrenia experience persistent psychotic symptoms despite adequate trials of antipsychotic treatment, and are considered to have treatment-resistant schizophrenia (TRS). Clozapine is the only medication to demonstrate efficacy for psychotic symptoms in such patients. However, clozapine is not effective in 40%-70% of patients with TRS and it has significant limitations in terms of potentially life-threatening side effects and the associated monitoring. Accordingly, a number of pharmacological and non-pharmacological biological approaches for clozapine-resistant TRS have emerged. This article provides a brief updated critical review of recent therapeutic strategies for TRS, particularly for clozapine-resistant TRS, which include pharmacotherapy, electroconvulsive therapy, repetitive transcranial magnetic stimulation, and transcranial direct current stimulation.

Augmentation strategies in partial responder and/or treatment-resistant schizophrenia patients treated with clozapine

INTRODUCTION

Although clozapine (CLZ) is considered the best evidence-based therapeutic option for treatment of resistant schizophrenia patients, a significant proportion of CLZ-treated patients show a partial or inadequate response to treatment, leading to increased healthcare cost and poor quality of life for affected individuals.

AREAS COVERED

This paper comprises a review of main research in CLZ augmentation strategies for treatment-refractory schizophrenia, with a focus on research conducted between 1990 and 2014. Databases that were searched include: PubMed, CINAHL, EMBASE PsychINFO, AgeLine and Cochrane Database of Systematic Reviews. Primary search terms were 'clozapine augmentation', 'clozapine and add-on' and 'treatment-resistant schizophrenia', with cross reference to specific agents covered in this article. We reviewed the available evidence on CLZ augmentation with antipsychotics, antidepressants, mood stabilizers and other agents.

EXPERT OPINION

Many drugs have been evaluated as CLZ add-on therapies without demonstrating convincing efficacy in treating refractory schizophrenia symptoms. More research is needed to better define outcomes in schizophrenia, the topic of treatment-resistance and more well-designed trials are required to establish true efficacy and safety of CLZ augmentation strategies.