Association of Antipsychotic Polypharmacy and Two-Year All-Cause Mortality: A Population-Based Cohort Study of 33,221 Italian Continuous Users

Background: Differences in survival between patients treated with antipsychotic monotherapy vs. polytherapy are debated. This study aimed to examine the association of antipsychotic polytherapy with 2-year all-cause mortality in a population-based cohort. Methods: Data were retrieved from healthcare databases of four local health units of Lombardy, Italy. Subjects aged 18-79 years who received continuous antipsychotic prescriptions in 2018 were identified. Overall survival among patients with antipsychotic monotherapy vs. polytherapy was compared. A multivariate Cox PH model was used to estimate the association between antipsychotic therapy, or antipsychotic use (continuous vs. non-continuous), and all-cause mortality. Adjustments were made for the presence of metabolic disturbances, total antipsychotic dosage amount (olanzapine equivalent doses), age, and sex. Results: A total of 49,875 subjects receiving at least one prescription of antipsychotics during 2018 were identified. Among the 33,221 patients receiving continuative antipsychotic prescriptions, 1958 (5.9%) experienced death from any cause at two years. Patients with continuous antipsychotic use had a 1.13-point increased mortality risk compared with non-continuous users. Patients treated with antipsychotic polytherapy showed an adjusted mortality risk increased by 17% (95% CI: 2%, 33%) compared to monotherapy. Conclusions: The study highlights the potential risks associated with antipsychotic polypharmacy, emphasizing the importance of optimizing drug prescriptions to improve patient safety and reduce mortality rates in individuals receiving antipsychotic therapy.

Metabolic side effects in persons with schizophrenia during mid- to long-term treatment with antipsychotics: a network meta-analysis of randomized controlled trials

Metabolic side effects of antipsychotic drugs can have serious health consequences and may increase mortality. Although persons with schizophrenia often take these drugs for a long time, their mid- to long-term metabolic effects have been studied little so far. This study aimed to evaluate the mid- to long-term metabolic side effects of 31 antipsychotics in persons with schizophrenia by applying a random-effects Bayesian network meta-analysis. We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials (up to April 27, 2020) and PubMed (up to June 14, 2021). We included published and unpublished, open and blinded randomized controlled trials with a study duration >13 weeks which compared any antipsychotic in any form of administration with another antipsychotic or with placebo in participants diagnosed with schizophrenia. The primary outcome was weight gain measured in kilograms. Secondary outcomes included "number of participants with weight gain", fasting glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. We identified 137 eligible trials (with 35,007 participants) on 31 antipsychotics, with a median follow-up of 45 weeks. Chlorpromazine produced the most weight gain (mean difference to placebo: 5.13 kg, 95% credible interval, CrI: 1.98 to 8.30), followed by clozapine (4.21 kg, 95% CrI: 3.03 to 5.42), olanzapine (3.82 kg, 95% CrI: 3.15 to 4.50), and zotepine (3.87 kg, 95% CrI: 2.14 to 5.58). The findings did not substantially change in sensitivity and network meta-regression analyses, although enriched design, drug company sponsorship, and the use of observed case instead of intention-to-treat data modified the mean difference in weight gain to some extent. Antipsychotics with more weight gain were often also among the drugs with worse outcome in fasting glucose and lipid parameters. The confidence in the evidence ranged from low to moderate. In conclusion, antipsychotic drugs differ in their propensity to induce metabolic side effects in mid- to long-term treatment. Given that schizophrenia is often a chronic disorder, these findings should be given more consideration than short-term data in drug choice.

Metabolic Side Effects of Olanzapine in Patients With Psychotic Disorders in Oman: A Retrospective Cohort Study

We evaluated the impact of olanzapine on metabolic changes in patients with psychotic disorders. This was a retrospective cohort study involving patients prescribed olanzapine and attending Sultan Qaboos University Hospital (Muscat, Oman). Patients were followed up retrospectively from March 2006 until April 2021. Cardiovascular treatment targets were evaluated as per the 2019 European Society of Cardiology guidelines. We enrolled 253 patients (mean age: 40±17 years). Olanzapine monotherapy was associated with increased body weight (+8 kg; 95% confidence interval (CI): 6-9; P < .001), body mass index (+3 kg/m²; 95% CI: 2-4; P < .001), total cholesterol (+.4 mmol/L; 95% CI: .3-.5; P < .001), low-density lipoprotein cholesterol (LDL-C) (+.3 mmol/L; 95% CI: .1-.4; P < .001), fasting triglycerides (+.2 mmol/L; 95% CI: .1-.3; P<.001), fasting glucose (+.6 mmol/L; 95% CI: .4-.7; P< .001), HbA1c (+.3%; 95% CI: .2-.4; P < .001), systolic blood pressure (BP) (+9 mmHg; 95% CI: 6-12; P < .001) and diastolic BP (+4 mmHg; 95% CI: 2-6; P < .001) levels. Cardiovascular therapeutic goals were attained in 38% (n = 97), 61% (n = 154), 71% (n = 180), and 59% (n = 150) for LDL-C, non-high-density lipoprotein cholesterol, triglycerides, and BP, respectively. Olanzapine was associated with adverse metabolic changes. Therefore, many patients were not at their target cardiovascular treatment goals.

Interventions to Improve Metabolic Risk Screening Among Children and Adolescents on Antipsychotic Medication: A Systematic Review

Objective: Antipsychotic use among youth is common and is associated with metabolic side effects such as weight gain. Guidelines recommend periodic screening of metabolic measures in youth prescribed antipsychotics; however, a guideline-to-practice gap exists. We systematically reviewed the literature to synthesize the knowledge from interventions that aim to improve antipsychotic metabolic screening. We described the interventions' effect on screening rates, the strategies used for improvement, and study quality. Methods: We conducted a systematic review of studies that attempted to improve antipsychotic metabolic risk screening practices among pediatric populations published between 2004 and August 2019. We included studies with an improvement intervention that compared screening rates before and after the intervention. We extracted data about study characteristics, screening rates in pre- and postintervention groups, strategies used to influence screening practices, and assessed studies' risk of bias. This review was prospectively registered with PROSPERO #CRD42018088241. Results: We identified six studies that demonstrated modest improvements in median metabolic screening rates for waist circumference (0%-16%), glucose (9%-39%), and lipids (11%-37%). Median postintervention screening rates were higher for weight and blood pressure (84% and 72.5%) compared with glucose and lipids (39% and 37%). Interventions used a variety of improvement strategies to address patient-, provider-, and organization-level barriers for screening, including increasing patient and provider knowledge regarding antipsychotic side effects, fostering social clinical environments that promote screening, and organizational commitment for screening antipsychotic-treated youth. All interventions were deemed at high risk of bias due to uncontrolled design and lack of adjustment for confounders. Conclusions: Included studies reported partial success in improving antipsychotic screening rates but were of poor methodological quality. Common improvement strategies may affect provider behavior to conduct metabolic screening, but these need to be tailored to local resources and organization structure. Future studies need to use rigorous methodology and theory-informed improvement strategies aligned with organizational actions to prioritize safe and judicious practice of antipsychotics among pediatric populations.

Differential Effects of Acute Treatment With Antipsychotic Drugs on Peripheral Catecholamines

Antipsychotic drugs represent the most effective treatment for chronic psychotic disorders. The newer second generation drugs offer the advantage of fewer neurological side-effects compared to prior drugs, but many cause serious metabolic side-effects. The underlying physiology of these side-effects is not well-understood, but evidence exists to indicate that the sympathetic nervous system may play an important role. In order to examine this possibility further, we treated separate groups of adult female rats acutely with either the first generation antipsychotic drug haloperidol (0.1 or 1 mg/kg) or the second generation drugs risperidone (0.25 or 2.5 mg/kg), clozapine (2 or 20 mg/kg), olanzapine (3 or 15 mg/kg) or vehicle by intraperitoneal injection. Blood samples were collected prior to drug and then 30, 60, 120, and 180 mins after treatment. Plasma samples were assayed by HPLC-ED for levels of norepinephrine, epinephrine, and dopamine. Results confirmed that all antipsychotics increased peripheral catecholamines, although this was drug and dose dependent. For norepinephrine, haloperidol caused the smallest maximum increase (+158%], followed by risperidone (+793%), olanzapine (+952%) and clozapine (+1,684%). A similar pattern was observed for increases in epinephrine levels by haloperidol (+143%], olanzapine (+529%), risperidone (+617%) then clozapine (+806%). Dopamine levels increased moderately with olanzapine [+174%], risperidone [+271%], and clozapine [+430%]. Interestingly, levels of the catecholamines did not correlate strongly with each other prior to treatment at baseline, but were increasingly correlated after treatment as time proceeded. The results demonstrate antipsychotics can potently regulate peripheral catecholamines, in a manner consistent with their metabolic liability.

Preclinical and Clinical Sex Differences in Antipsychotic-Induced Metabolic Disturbances: A Narrative Review of Adiposity and Glucose Metabolism

Antipsychotic (AP) medications are associated with an increased risk of developing metabolic side effects including weight gain, type 2 diabetes (T2D), dyslipidemia, and hypertension. In the majority of clinical studies, females on APs are noted to gain more weight, and are more likely to be diagnosed with metabolic syndrome when compared to males. However, the data is less clear when comparing sex disparities associated with other specific AP-induced metabolic risk factors. Accumulating evidence has demonstrated a role for AP-induced adipose tissue accumulation as well as whole body glucose dysregulation in male models that is independent of changes in body weight. The purpose of this narrative review is to explore the susceptibility of males and females to changes in adiposity and glucose metabolism across clinical and preclinical models of AP treatment. It is important that future research examining AP-induced metabolic side effects analyzes outcomes by sex to help clarify risk and identify the mechanisms of adverse event development to improve safe prescribing of medications.

Antipsychotic Drugs: From Receptor-binding Profiles to Metabolic Side Effects

BACKGROUND

Antipsychotic-induced metabolic side effects are major concerns in psychopharmacology and clinical psychiatry. Their pathogenetic mechanisms are still not elucidated.

METHODS

Herein, we review the impact of neurotransmitters on metabolic regulation, providing insights into antipsychotic-induced metabolic side effects.

RESULTS

Antipsychotic drugs seem to interfere with feeding behaviors and energy balance, processes that control metabolic regulation. Reward and energy balance centers in central nervous system constitute the central level of metabolic regulation. The peripheral level consists of skeletal muscles, the liver, the pancreas, the adipose tissue and neuroendocrine connections. Neurotransmitter receptors have crucial roles in metabolic regulation and they are also targets of antipsychotic drugs. Interaction of antipsychotics with neurotransmitters could have both protective and harmful effects on metabolism.

CONCLUSION

Emerging evidence suggests that antipsychotics have different liabilities to induce obesity, diabetes and dyslipidemia. However this diversity cannot be explained merely by drugs'pharmacodynamic profiles, highlighting the need for further research.

Short-term effects of the DASH diet in adults with moderate chronic kidney disease: a pilot feeding study

Background

Although the Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure (BP) for adults with normal kidney function, evidence is lacking regarding its safety and efficacy in chronic kidney disease (CKD). We aimed to test the effects of the DASH diet on serum electrolytes and BP in adults with moderate CKD.

Methods

In a prospective before–after feeding study, 11 adults with an estimated glomerular filtration rate of 30–59 mL/min/1.73 m² and medication-treated hypertension were provided a reduced-sodium, run-in diet for 1 week followed by a reduced-sodium, DASH diet for 2 weeks. Changes in serum electrolytes and BP were compared pre–post DASH.

Results

Eleven participants underwent feeding; 1 completed 1 week and 10 completed 2 weeks of DASH. Compared with baseline, DASH modestly increased serum potassium at 1 week (mean ± standard deviation, +0.28 ± 0.4 mg/dL; P = 0.043) but had no significant effect on potassium at 2 weeks (+0.15 ± 0.28 mg/dL; P = 0.13). Serum bicarbonate was reduced (−2.5 ± 3.0 mg/dL; P = 0.03) at 2 weeks. Neither incident hyperkalemia nor new onset metabolic acidosis was observed. Clinic BP and mean 24-h ambulatory BP was unchanged. DASH significantly reduced mean nighttime BP (−5.3 ± 5.8 mmHg; P = 0.018), and enhanced percent declines in both nocturnal systolic BP (−2.1% to −5.1%; P = 0.004) and diastolic BP (−3.7% to −10.0%; P = 0.008).

Conclusions

These pilot data suggest that a reduced-sodium DASH dietary pattern does not cause acute metabolic events in adults with moderate CKD and may improve nocturnal BP. Definitive studies are needed to determine long-term effects of DASH in CKD.

Lithium or Valproate Adjunctive Therapy to Second-generation Antipsychotics and Metabolic Variables in Patients With Schizophrenia or Schizoaffective Disorder

OBJECTIVE

People with schizophrenia are at greater risk for cardiovascular disease and their overall mortality rate is elevated compared to the general population. The metabolic side effects of antipsychotic medications have been widely studied; however, the effect of adding conventional mood stabilizers, such as lithium and valproate, to antipsychotic medication has not been assessed in terms of metabolic risk. The primary purpose of this secondary analysis was to examine whether treatment with lithium or valproate in addition to a second-generation antipsychotic is associated with poorer metabolic outcomes than treatment with a second-generation antipsychotic without lithium or depakote.

METHODS

Baseline data from 3 studies, which included measurement of body mass index, waist circumference, fasting glucose, insulin, homeostatic model assessment of insulin resistance, insulin sensitivity index, glucose utilization, and acute insulin response to glucose, were included in the analysis.

RESULTS

No differences were found between those taking lithium or valproate and those who were not in terms of fasting glucose, fasting insulin, and homeostatic model assessment of insulin resistance. Insulin sensitivity was lower among participants taking lithium or valproate. Participants taking lithium or valproate had a higher body mass index than those not taking conventional mood stabilizers, although the difference did not reach statistical significance.

CONCLUSIONS

These cross-sectional findings suggest it may be beneficial to monitor insulin sensitivity and body mass index in patients taking lithium or valproate in combination with a second-generation antipsychotic.

Among the severely mentally ill, who responds to ziprasidone?

So far, demographic variables have not consistently been found to predict clinical response to antipsychotics. This study examines some differences in response to ziprasidone, which has been shown to be effective, with a better metabolic side effect profile, but was little used in New York State Hospitals. The aim was to study state hospital patients switched to ziprasidone. The results led to questions about different responses in different groups. Subjects from state hospitals who needed a change of antipsychotic participated in this openlabel 8 week trial of up to 240 mg ziprasidone. Analyses included comparisons of the very different results from two sites. Of the 36 study subjects, 12 terminated early. The 17 outpatients from Buffalo, who were older and on lower doses of antipsychotics pre-study, improved significantly. The 19 inpatients from the Bronx, overall younger and on higher pre-study doses, barely changed. Improvements in PANSS total score were significantly associated with older age, greater baseline severity, and lower doses of antipsychotics pre-study. The subjects improved on metabolic parameters. The results suggest that ziprasidone may be just as effective as previous antipsychotics taken by these severely mentally ill patients, and with fewer metabolic side effects.

Effects of the Dietary Approaches to Stop Hypertension (DASH) Eating Plan on the Metabolic Side Effects of Corticosteroid Medications

OBJECTIVE

We aimed to determine the effects of the Dietary Approaches to Stop Hypertension (DASH) diet on the metabolic side effects of corticosteroid medication use.

DESIGN

A randomized clinical trial was undertaken in 60 patients on corticosteroid therapy for 10 weeks. Patients were randomly assigned to a DASH or control diet. Carbohydrate, protein, and fat in both groups were 50-60%, 15-20%, 30%, respectively. DASH diet was a diet rich in fruits, vegetables, whole grains, low-fat dairy products, and low in total and saturated fat and cholesterol, refined grains, and also sweets. Fasting blood samples were collected to determine blood glucose and lipid profile. Blood pressure and anthropometric measurements were measured based on the standard guidelines.

RESULTS

The mean age and body mass index (BMI) were 31.1 ± 3.6 year and 26.9 ± 2.6 kg/m(2), respectively. There were no significant differences between age and BMI in two groups at baseline. No significant difference was observed in body weight and waist circumference following the DASH diet compared to control diet. Systolic and diastolic blood pressures were significantly different following the DASH eating pattern (P = 0.04). Serum total cholesterol and fasting blood glucose significantly decreased in those following the DASH diet after adjustment for potential confounders.

CONCLUSION

The DASH diet had beneficial effects on several metabolic side effects among patients using corticosteroid medications.

A Randomized Comparison of Aripiprazole and Risperidone for the Acute Treatment of First-Episode Schizophrenia and Related Disorders: 3-Month Outcomes

Research findings are particularly important for medication choice for first-episode patients as individual prior medication response to guide treatment decisions is unavailable. We describe the first large-scale double-masked randomized comparison with first-episode patients of aripiprazole and risperidone, 2 commonly used first-episode treatment agents. One hundred ninety-eight participants aged 15-40 years with schizophrenia, schizophreniform disorder, schizoaffective disorder or psychotic disorder Not Otherwise Specified, and who had been treated in their lifetime with antipsychotics for 2 weeks or less were randomly assigned to double-masked aripiprazole (5-30 mg/d) or risperidone (1-6 mg/d) and followed for 12 weeks. Positive symptom response rates did not differ (62.8% vs 56.8%) nor did time to response. Aripiprazole-treated participants had better negative symptom outcomes but experienced more akathisia. Body mass index change did not differ between treatments but advantages were found for aripiprazole treatment for total and low-density lipoprotein cholesterol, fasting glucose, and prolactin levels. Post hoc analyses suggested advantages for aripiprazole on depressed mood. Overall, if the potential for akathisia is a concern, low-dose risperidone as used in this trial maybe a preferred choice over aripiprazole. Otherwise, aripiprazole would be the preferred choice over risperidone in most situations based upon metabolic outcome advantages and some symptom advantages within the context of similar positive symptom response between medications.

Community adherence to schizophrenia treatment and safety monitoring guidelines

The 2003 Schizophrenia Patient Outcomes Research Team (PORT) treatment recommendations and the Mount Sinai Conference Safety Monitoring recommendations generated guidelines for pharmacological treatment of schizophrenia and monitoring of antipsychotic side effects. This study examined rate of recommendation adherence and impact of adherence on outcomes of outpatients with schizophrenia or schizoaffective disorder in community mental health centers. Clinical practice was assessed as conformant, nonconformant, or not applicable. Treatment practices were conformant for antipsychotic dose (83%); use of antiparkinsonian (97%), antidepressant (100%), and antianxiety agents (90%) but not clozapine for residual positive symptoms (31%); and monitoring weight gain (48%), glucose dysregulation (53%), hyperlipidemia (34%), or extrapyramidal symptoms (11%). Community mental health center treatment practices were largely conformant with the 2003 Schizophrenia PORT treatment recommendations. There is less evidence that patients who receive treatment in the community are adequately monitored for antipsychotic side effects per the Mount Sinai recommendations.

Monitoring and managing metabolic effects of antipsychotics: a cluster randomized trial of an intervention combining evidence-based quality improvement and external facilitation

BACKGROUND

Treatment of psychotic disorders consists primarily of second generation antipsychotics, which are associated with metabolic side effects such as overweight/obesity, diabetes, and dyslipidemia. Evidence-based clinical practice guidelines recommend timely assessment and management of these conditions; however, research studies show deficits and delays in metabolic monitoring and management for these patients. This protocol article describes the project 'Monitoring and Management for Metabolic Side Effects of Antipsychotics,' which is testing an approach to implement recommendations for these practices.

METHODS/DESIGN

This project employs a cluster randomized clinical trial design to test effectiveness of an evidence-based quality improvement plus facilitation intervention. Eligible study sites were VA Medical Centers with ≥300 patients started on a new antipsychotic prescription in a six-month period. A total of 12 sites, matched in pairs based on scores on an organizational practice survey, were then randomized within pairs to intervention or control conditions.Study participants include VA employees involved in metabolic monitoring and management of patients treated with antipsychotics at participating sites. The intervention involves researchers partnering with clinical stakeholders to facilitate tailoring of local implementation strategies to address barriers to metabolic side-effect monitoring and management. The intervention includes a Design Phase (initial site visit and subsequent development of a local implementation plan); Implementation Phase (guided by an experienced external facilitator); and a Sustainability Phase. Evaluation includes developmental, implementation-focused, progress-focused and interpretative formative evaluation components, as well as summative evaluation. Evaluation methods include surveys, qualitative data collection from provider participants, and quantitative data analysis of data for all patients prescribed a new antipsychotic medication at a study site who are due for monitoring or management of metabolic side effects during the study phases. Changes in rates of recommended monitoring and management actions at intervention and control sites will be compared using time series analyses.

DISCUSSION

Improving monitoring for metabolic side effects of antipsychotics, as well as promoting timely evidence-based management when these effects emerge, will lead to improved patient safety and long-term outcomes. This article discusses key strengths and challenges of the study.

TRIAL REGISTRATION

NCT01875861.

Effects of switching from olanzapine, quetiapine, and risperidone to aripiprazole on 10-year coronary heart disease risk and metabolic syndrome status: results from a randomized controlled trial

PURPOSE

This study examined the clinical significance of switching from olanzapine, quetiapine, or risperidone to aripiprazole by examining changes in predicted risk of cardiovascular disease (CVD) according to the Framingham Risk Score (FRS) and metabolic syndrome status. FRS estimates 10-year risk of "hard" coronary heart disease (CHD) outcomes (myocardial infarction and coronary death) while metabolic syndrome is associated with increased risk of CVD, stroke, and diabetes mellitus.

METHOD

Changes in FRS and metabolic syndrome status were compared between patients with BMI ≥ 27 and non-HDL-C ≥ 130 mg/dL randomly assigned to stay on stable current treatment (olanzapine, quetiapine, or risperidone) or switch to treatment with aripiprazole with 24 weeks of follow-up. All study participants were enrolled in a behavioral program that promoted healthy diet and exercise.

RESULTS

The pre-specified analyses included 89 switchers and 98 stayers who had post-baseline measurements needed to assess changes. Least squares mean estimates of 10-year CHD risk decreased more for the switch (from 7.0% to 5.2%) than the stay group (from 7.4% to 6.4%) (p = 0.0429). The odds ratio for having metabolic syndrome (stay vs. switch) at the last observation was 1.748 (95% CI 0.919, 3.324, p = 0.0885).

CONCLUSION

Switching from olanzapine, quetiapine, or risperidone to aripiprazole was associated with larger reductions in predicted 10-year risk of CHD than the behavioral program alone. The advantage of switching on metabolic syndrome was not statistically significant. The benefits of switching must be balanced against its risks, which in this study included more discontinuations of the study treatment but no significant increase in symptoms or hospitalizations.

Genomewide pharmacogenomic study of metabolic side effects to antipsychotic drugs

Understanding individual differences in the susceptibility to metabolic side effects as a response to antipsychotic therapy is essential to optimize the treatment of schizophrenia. Here, we perform genomewide association studies (GWAS) to search for genetic variation affecting the susceptibility to metabolic side effects. The analysis sample consisted of 738 schizophrenia patients, successfully genotyped for 492K single nucleotide polymorphisms (SNPs), from the genomic subsample of the Clinical Antipsychotic Trial of Intervention Effectiveness study. Outcomes included 12 indicators of metabolic side effects, quantifying antipsychotic-induced change in weight, blood lipids, glucose and hemoglobin A1c, blood pressure and heart rate. Our criterion for genomewide significance was a pre-specified threshold that ensures, on average, only 10% of the significant findings are false discoveries. A total of 21 SNPs satisfied this criterion. The top finding indicated that a SNP in Meis homeobox 2 (MEIS2) mediated the effects of risperidone on hip circumference (q=0.004). The same SNP was also found to mediate risperidone's effect on waist circumference (q=0.055). Genomewide significant finding were also found for SNPs in PRKAR2B, GPR98, FHOD3, RNF144A, ASTN2, SOX5 and ATF7IP2, as well as in several intergenic markers. PRKAR2B and MEIS2 both have previous research indicating metabolic involvement, and PRKAR2B has previously been shown to mediate antipsychotic response. Although our findings require replication and functional validation, this study shows the potential of GWAS to discover genes and pathways that potentially mediate adverse effects of antipsychotic medication.

Antipsychotic drug mechanisms: links between therapeutic effects, metabolic side effects and the insulin signaling pathway

The exact therapeutic mechanism of action of antipsychotic drugs remains unclear. Recent evidence has shown that second-generation antipsychotic drugs (SGAs) are differentially associated with metabolic side effects compared to first-generation antipsychotic drugs (FGAs). Their proclivity to cause metabolic disturbances correlates, to some degree, with their comparative efficacy. This is particularly the case for clozapine and olanzapine. In addition, the insulin signaling pathway is vital for normal brain development and function. Abnormalities of this pathway have been found in persons with schizophrenia and antipsychotic drugs may ameliorate some of these alterations. This prompted us to hypothesize that the therapeutic antipsychotic and adverse metabolic effects of antipsychotic drugs might be related to a common pharmacologic mechanism. This article reviews insulin metabolism in the brain and related abnormalities associated with schizophrenia with the goals of gaining insight into antipsychotic drug effects and possibly also into the pathophysiology of schizophrenia. Finally, we speculate about one potential mechanism of action (that is, functional selectivity) that would be consistent with the data reviewed herein and make suggestions for the future investigation that is required before a therapeutic agent based on these data can be realized.

A case series: evaluation of the metabolic safety of aripiprazole

Metabolic abnormalities occur frequently in patients treated with antipsychotics and are of growing concern to clinicians. This study sought to determine whether antipsychotic-associated metabolic abnormalities identified through intensive monitoring can be reversed by switching to aripiprazole. Recent evidence suggests that aripiprazole may exhibit a favorable metabolic safety profile. The study population is a subset of a large (n > 500) ongoing prospective cohort. Thirty-one consecutive patients with schizophrenia who were started on aripiprazole were included in the study. All patients underwent an extensive metabolic evaluation, including an oral glucose tolerance test, at baseline, at 6 weeks, and at 3 months post switch. Metabolic abnormalities were defined as any of the following: new onset diabetes, impaired fasting glucose, impaired glucose tolerance, metabolic syndrome (MetS) according to various definitions, and dyslipidemia. After 3 months of treatment with aripiprazole (mean daily dose 16.3 mg), there was a significant decrease in body weight, body mass index, and waist circumference. There was a significant reduction in fasting glucose, fasting insulin, insulin resistance index, and serum lipids levels (cholesterol, triglycerides, low-density lipoprotein (LDL), LDL/HDL, Chol/HDL, and non-HDL cholesterol). There was also a significant reduction in prolactin levels. All 7 cases of recent onset diabetes were reversed at 3 months follow-up. The MetS was reversed in 50% of patients at 3 months follow-up. Our results support the reversibility of recent onset diabetes on antipsychotic medication when detected early and followed by a switch to aripiprazole.