Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although still considered more of a cosmetic problem by both the general public and some areas of the medical community, overweight and obesity have reached epidemic proportions worldwide. Overweight and obesity have not only a significant psychological impact but also result in an increased risk for development of numerous chronic and sometimes fatal diseases. The morbidity from obesity-associated disorders increases with higher body mass index and begins within the normal weight range. The costs (direct and indirect) associated with treating obesity and its comorbid conditions are notable and increasing. Obesity rates in patients with schizophrenia are at least as high, if not higher, than in the general population. This article reviews the epidemiology and burden of obesity and its associated comorbid disorders. The guidelines from the National Heart, Lung, and Blood Institute of the National Institutes of Health for diagnosing and treating obesity are also discussed.
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PMID:Epidemiology, morbidity, and treatment of overweight and obesity. 1160 81

Atypical antipsychotics such as clozapine represent a significant improvement over typical antipsychotics in the treatment of schizophrenia, particularly regarding extrapyramidal symptoms. Despite their benefits, use is limited by the occurrence of adverse reactions such as sedation and weight gain. This article provides a comprehensive review and discussion of obesity-related pathways and integrates these with the known mechanisms of atypical antipsychotic action to identify candidate molecules that may be disrupted during antipsychotic treatment. Novel preliminary data are presented to genetically dissect these obesity pathways and elucidate the genetic contribution of these candidate molecules to clozapine-induced weight gain. There is considerable variability among individuals with respect to the ability of clozapine to induce weight gain. Genetic predisposition to clozapine-induced weight gain has been suggested. Therefore, genetic variation in these candidate molecules may predict patient susceptibility to clozapine-induced weight gain. This hypothesis was tested for 10 genetic polymorphisms across 9 candidate genes, including the serotonin 2C, 2A, and 1A receptor genes (HTR2C/2A/1A); the histamine H1 and H2 receptor genes (H1R/H2R); the cytochrome P450 1A2 gene (CYPIA2); the beta3 and alpha,alpha-adrenergic receptor genes (ADRB3/ADRAIA); and tumor necrosis factor alpha (TNF-alpha). Prospective weight gain data were obtained for 80 patients with schizophrenia who completed a structured clozapine trial. Trends were observed for ADRB3, ADRA1A, TNF-alpha, and HTR2C; however, replication in larger, independent samples is required. Although in its infancy, psychiatric pharmacogenetics will in the future aid clinical practice in the prediction of response and side effects, such as antipsychotic-induced weight gain, and minimize the current "trial and error" approach to prescribing.
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PMID:Genetic dissection of atypical antipsychotic-induced weight gain: novel preliminary data on the pharmacogenetic puzzle. 1160 85

The prevalence of obesity in inpatients of a German psychiatric rehabilitation center for adolescents and young adults (mean age 19.5 years) is assessed and set into relationship to diagnosis and medication regimen. In a cross-sectional naturalistic study body weights and heights of 151 inpatients, 109 of whom presented with ICD-10 schizophrenia spectrum disorders, were measured for the calculation of body mass indices (BMI, kg/m2); current medication regimen including the duration of treatment was assessed from medical records. BMIs were plotted into gender- and age-specific BMI-percentiles representative for the German population. Among the whole study population, obesity (BMI > or =90th percentile) was apparent in 44/98 (45%) of the male and in 31/53 (59%) of the female inpatients (overall: 50%). With respect to schizophrenia spectrum disorders, 36/70 (51%) males and 25/39 (64%) females (overall: 56%) were obese in contrast to 14/42 (33%) among the individuals without schizophrenia. Set into relationship to the treatment groups, the prevalence rates of obesity were 64% in patients treated with clozapine (n=69), 56% for other atypical antipsychotics (olanzapine, sulpiride, risperidone; n=27), 30% for classic antipsychotics (haloperidol, flupentixol, perazine; n=20) and 28% for the currently drug-free group (n=25). Together with other published findings in adults, these results suggest an increased prevalence of obesity among young patients with schizophrenia and especially among patients chronically treated with atypical antipsychotics.
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PMID:Prevalence of obesity in adolescent and young adult patients with and without schizophrenia and in relationship to antipsychotic medication. 1168 41

Type 2 diabetes mellitus and impaired glucose tolerance are associated with antipsychotic treatment. Risk factors for type 2 diabetes and impaired glucose tolerance include abdominal adiposity, age, ethnic status, and certain neuropsychiatric conditions. While impaired glucose metabolism was first described in psychotic patients prior to the introduction of antipsychotic medications, treatment with antipsychotic medications is associated with impaired glucose metabolism, exacerbation of existing type 1 and 2 diabetes, new-onset type 2 diabetes mellitus, and diabetic ketoacidosis, a severe and potentially fatal metabolic complication. The strength of the association between antipsychotics and diabetes varies across individual medications, with the largest number of reports for chlorpromazine, clozapine, and olanzapine. Recent controlled studies suggest that antipsychotics can impair glucose regulation by decreasing insulin action, although effects on insulin secretion are not ruled out. Antipsychotic medications induce weight gain, and the potential for weight gain varies across individual agents with larger effects observed again for agents like chlorpromazine, clozapine, and olanzapine. Increased abdominal adiposity may explain some treatment-related changes in glucose metabolism. However, case reports and recent controlled studies suggest that clozapine and olanzapine treatment may also be associated with adverse effects on glucose metabolism independent of adiposity. Dyslipidemia is a feature of type 2 diabetes, and antipsychotics such as clozapine and olanzapine have also been associated with hypertriglyceridemia, with agents such as haloperidol, risperidone, and ziprasidone associated with reductions in plasma triglycerides. Diabetes mellitus is associated with increased morbidity and mortality due to both acute (e.g., diabetic ketoacidosis) and long-term (e.g., cardiovascular disease) complications. A progressive relationship between plasma glucose levels and cardiovascular risk (e.g., myocardial infarction, stroke) begins at glucose levels that are well below diabetic or "impaired" thresholds. Increased adiposity and dyslipidemia are additional, independent risk factors for cardiovascular morbidity and mortality. Patients with schizophrenia suffer increased mortality due to cardiovascular disease, with presumed contributions from a number of modifiable risk factors (e.g., smoking, sedentary lifestyle, poor diet, obesity, hyperglycemia, and dyslipidemia). Patients taking antipsychotic medications should undergo regular monitoring of weight and plasma glucose and lipid levels, so that clinicians can individualize treatment decisions and reduce iatrogenic contributions to morbidity and mortality.
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PMID:Hyperglycemia and antipsychotic medications. 1180 85

The advent of the novel or atypical antipsychotic drugs has improved the treatment and quality of life for many individuals. However, many of these newer agents confer a degree of weight gain that is both greater than conventional antipsychotics and of a clinically meaningful magnitude. To better place this issue into perspective, we evaluated body mass index (BMI; kg/m2) levels and the prevalence of overweight and obesity among schizophrenic versus non-schizophrenic individuals among nationally representative samples of the US adult population and evaluated whether there were changes in these rates during the decade from 1987 to 1996, a period in which use of novel/atypical agents increased. Results showed that mean BMI for individuals with schizophrenia is significantly higher than individuals who are not schizophrenic. The non-schizophrenic population shows steady and significant gains in BMI from 1987 to 1996 both as a whole and when stratified by gender and age. In contrast, time trends among the population of schizophrenic individuals show a more complex pattern. Specifically, for most groups, there is little evidence of a general trend in BMI over time. However, among females with schizophrenia ages 18-30, BMI has increased dramatically and significantly causing a much higher obesity rate among young women with schizophrenia in recent years relative to their non-schizophrenic counterparts. The mechanism that underlies this weight age and sex specific time trend is unclear.
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PMID:Changes in body mass index for individuals with and without schizophrenia, 1987-1996. 1204 51

Individuals with schizophrenia have standardised mortality rates which are double that of the general population. In addition to suicide, high rates of cardiovascular and respiratory disease contribute to this raised mortality rate. Although clozapine has been reported to improve psychotic symptoms and decrease suicide rates, attention has recently focussed on its potential to increase cardiovascular risk factors including obesity, dyslipidemia and diabetes mellitus. This study aimed to ascertain the prevalence of these risk factors in a cohort of Irish outpatients treated with clozapine.
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PMID:Prevalence of obesity, lipid and glucose abnormalities in outpatients prescribed clozapine. 1209 Apr 43

The D2 dopamine receptor (DRD2) has been one of the most extensively investigated gene in neuropsychiatric disorders. After the first association of the TaqI A DRD2 minor (A1) allele with severe alcoholism in 1990, a large number of international studies have followed. A meta-analysis of these studies of Caucasians showed a significantly higher DRD2 A1 allelic frequency and prevalence in alcoholics when compared to controls. Variants of the DRD2 gene have also been associated with other addictive disorders including cocaine, nicotine and opioid dependence and obesity. It is hypothesized that the DRD2 is a reinforcement or reward gene. The DRD2 gene has also been implicated in schizophrenia, posttraumatic stress disorder, movement disorders and migraine. Phenotypic differences have been associated with DRD2 variants. These include reduced D2 dopamine receptor numbers and diminished glucose metabolism in brains of subjects who carry the DRD2 A1 allele. In addition, pleiotropic effects of DRD2 variants have been observed in neurophysiologic, neuropsychologic, stress response, personality and treatment outcome characteristics. The involvement of the DRD2 gene in certain neuropsychiatric disorders opens up the potential of a targeted pharmacogenomic approach to the treatment of these disorders.
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PMID:D2 dopamine receptor gene in psychiatric and neurologic disorders and its phenotypes. 1249 24

The strategy in the choice of antipsychotic agent must take into account the hepatic tolerance according to non-negligible incidence of liver disorders among psychiatric population (presence of risk factors like alcoholism, drugs of abuse intake, polymedication including potentially hepatotoxic drugs.). More than 1 000 drugs have been listed as being responsible of hepatic side effects; 16% of these agents were neuropsychiatric drugs. Antidepressive drugs (tricyclic agents or SSRI), mood stabilizing agents and neuroleptic drugs have been implicated in biological or/and clinical hepatotoxicity. For these reasons, some psychotropic agents have been withdrawn of the pharmaceutical market like alpidem or medifoxamine. Atrium*, sometimes used to correct tremor induced by neuroleptic drugs, has been withdrawn recently, as well. Isolated elevations of hepatic enzymes occur frequently with phenothiazines drugs (frequency evaluated to 20%) but also with other classes of neuroleptic agents, as well. On the contrary, clinical hepatitis have been more rarely described with neuroleptic drugs like phenothiazine agents (0,1-1%) or with haloperidol (0,002%). The definition of hepatotoxicity is based on biological parameters (elevation of alkaline phosphatase enzyme, SGPT, SGOT and GGT) or on clinical abnormalities (hepatitis, jaundice.). Clinical hepatitis could be either cytolytic or cholestatic. Clinical diagnosis and the research of its origin may include many investigations like abdominal ultrasonogram and percutaneous liver biopsy. The present article describes the cases of hepatic disorders reported with AAD (Atypical Antipsychotic Drugs), which are available in France (amisulpride, clozapine, olanzapine, risperidone). This new pharmacological class of antipsychotic drugs has showed great interest to improve negative symptoms of schizophrenia and to reduce disabling side effects like dystonia. According to the bibliographic data available, the following points and information must be clinically taken into account. Frequency of hepatic troubles: according to the bibliographic data, AAD appeared generally well tolerated in most cases. The frequency of hepatic troubles remains in general very low or rare. The cases published were observed with clozapine, olanzapine and risperidone. Nevertheless, some authors have observed higher frequency of hepatic enzymes elevation with some AAD. In an investigation comparing hepatic tolerance of clozapine (n=167) versus haloperidol (n=71), 37,3% of clozapine treated patients showed a relevant SGPT increase versus 16,6% with haloperidol. Nature of the hepatic troubles: among the clinical observations, asymptomatic biological disorders of the hepatic function are generally described but cytolytic or cholestatic hepatitis were reported, as well. Symptomatic hepatic dysfunctions were, sometimes, associated with other disorders like convulsions, pneumonia or malignant syndrome. Thus, hepatic check-up may be relevant in case of significant side-effect outcome. Delay time before the hepatic episode: hepatic injuries generally occurred within the first weeks of treatment but this delay highly varied in the literature from 1 to 8 weeks, 12 days to 5 months, 1 day to 17 months for clozapine, olanzapine and risperidone, respectively. These delay times are very similar to those observed with other psychotropic drugs. Reversibility of the hepatic troubles and rechallenge of the responsible agent: all cases were reversible after the AAD withdrawal except with one patient (39 years old) treated by clozapine (350 mg/day) who developed a fulminant and irreversible hepatitis after 8 weeks of monotherapy. In most cases, the AAD was withdrawn after the hepatic episode according to the significant risk of irreversible alteration. Nevertheless, normalization of hepatic enzymes has been described despite AAD maintenance at the same dosage or after dosage reduction. Rechallenge of clozapine after a first episode was performed for three patients, only one redeveloped a new hepatic disorder. According to different authors, special care is required if maintenance or rechallenge of the agent is indispensable after a first episode of isolated hepatic enzyme elevation (i.e resistance or intolerance to other treatments). In this case, biological and clinical supervision has to be carefully scheduled, which demands a satisfactory compliance from the patient. On the contrary, in case of clinical hepatotoxicity, rechallenge or maintenance is absolutely inadvisable. Mechanism of the hepatic troubles: precise mechanisms of the hepatotoxicity remain unclear. Contrary to phenothiazine drugs, no information is available on the respective rule of the agents and their metabolites. Hypersensitivity syndrome or eosinophilia has been reported, suggesting a possible immuno-allergic mechanism. Presence of risk factors: risk factors have been retrieved, in some observations, like high daily dosage, high plasmatic concentration, age, alcoholism, obesity or antecedent of hepatic disorders like Gilbert syndrome. Special care is advisable with these patients. As hepatotoxicity has been observed after surdosage (or suicide attempt), a hepatic check-up has to be performed in these clinical situations. Co-medication with hepatotoxic drugs may increase the risk as it has been suggested. In many observations, co-medication made difficult the incrimination of the AAD in the hepatic disorders outcome. Monotherapy has the great advantage to make easier the withdrawal of the responsible agent and its substitution. As drugs of abuse like cocaine or ecstasy are notoriously responsible of hepatotoxicity, they represent a probable factor of risk. Moreover, their detection is fundamental during the clinical investigation. Conclusion - Diagnosis of toxic hepatitis is mainly based on the chronology between agent introduction and hepatic disorder onset but other causes must be excluded. Bibliographic data analysis greatly contributes to confirm toxic hepatitis diagnosis. Nevertheless, this article emphasized the limits of bibliographic review to compare drugs towards tolerance. Most of the bibliographic data were case-reports for which it was sometimes difficult to provide absolute evidence of the responsibility of the agent. Moreover, spontaneous notification to health national administration is rarely systematic, in particular with isolated elevation of hepatic enzymes, and even more rarely published in international reviews. Nevertheless, according to the present data available in the literature, systematic and regular hepatic survey does not seem necessary in absence of risk factors. As for other side effects, which may occur more or less rapidly, great advantages may be obtained from psycho-education programs associating the patients in order to detect the first symptoms. Because little long-term hepatic follow-up comparing AAD is available, controlled studies should be carried out to precise the frequency and the risk factors (covariables) to prevent hepatitis outcome.
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PMID:[Hepatic tolerance of atypical antipsychotic drugs]. 1250 67

Excessive body weight gain (BWG) is a common side effect of some typical and atypical antipsychotic drugs (APs). Convergent evidence suggests a hierarchy in the magnitude of BWG that may be induced by diverse agents, being very high for clozapine and olanzapine; high for quetiapine, zotepin, chlorpromazine, and thioridazine; moderate for risperidone and sertindole; and low for ziprazidone, amisulpiride, haloperidol, fluphenazine, pimozide, and molindone. BWG may be related to increased appetite that is due to drug interaction with the brain monoaminergic and cholinergic systems and to the metabolic/endocrine effects of hyperprolactinemia. Subjects with schizophrenia and bipolar disorders manifested a significantly high prevalence of diabetes, even before the introduction of atypical APs. However, clozapine and olanzapine appear to display a high propensity to induce glucose dysregulation and dyslipidemia. Sudden BWG, insulin resistance, increased appetite, and related endocrine changes also may be involved in the development of glucose intolerance and dyslipidemia in predisposed individuals. Patients should be informed of these side effects in order to prevent excessive BWG, and their blood glucose and lipids should be monitored before treatment and then at regular intervals. Nutritional advice must be given and regular physical exercise recommended. An appropriate selection of APs ought to be based on drug efficacy for specific patients and assessment of relevant risk factors such as propensity to gain weight; family or personal history of diabetes or hyperlipidemia; and elevated fasting serum glucose, lipid, or insulin levels. At present, there is no standardized pharmacological treatment for AP-induced BWG. Some studies have assessed the effects of agents such as amantadine, orlistat, metformin, nizatidine, and topiramate on AP-induced BWG. Further studies will provide tools to identify patients at high risk for obesity and metabolic abnormalities during AP administration. Excessive body weight gain (BWG), glucose intolerance, and dyslipidemia during treatment with antipsychotic drugs (APs) were reported in the late 1950s [14,101]. However, after 1990, interest in these problems increased noticeably, mainly because of the high propensity of some new atypical APs to induce these side effects (Fig.1). The APs are currently used in diverse mental disorders. Hence, excessive BWG and metabolic dysfunction are not exclusive of subjects with schizophrenia. In the case of bipolar disorders, AP-induced BWG may be additive to that induced by mood stabilizers [14,48,101]. The clinical features [2,14,24,133,139,140] and mechanisms [14,34,68,87,93,101,130] of BWG and metabolic dysfunction have been previously reviewed. In this article, we focus on a unified theory to explain these side effects, based on the interaction of APs with brain neurotransmitters involved in appetite regulation. This review comprises the following sections: 1) the clinical features of AP-induced BWG; 2) the effects of APs on carbohydrate and lipid metabolism in humans and experimental animals; 3) mechanisms involved in BWG, glucose, and lipid dysregulation; 4) strategies for prevention and treatment of these side effects; and 5) research perspectives in the field. The following sources were consulted: MEDLINE, Cochrane database system, and PsychINFO. Numerous articles referred to in leading articles also were consulted. The literature on this subject has increased so rapidly that it was impossible to include all the data recently published. For the first two sections, references that illustrate current controversies in the field were selected.
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PMID:Obesity and related metabolic abnormalities during antipsychotic drug administration: mechanisms, management and research perspectives. 1251 68

5-HT(2) family serotonin receptors, principal sites of action of serotonin in the brain, represent major molecular targets for drugs used in treating a variety of diseases including schizophrenia, depression, anxiety, eating disorders, obsessive-compulsive disorder, chronic pain conditions and obesity. The 5-HT(2) family of receptors has three members: 5-HT(2A), 5-HT(2B) and 5-HT(2C). Therefore, it is likely that subtype-selective compounds will be needed to avoid serious side effects and to enhance therapeutic indices. Unfortunately, recent insights into the structure and function of 5-HT(2A) receptors have revealed that structurally-diverse agonists and antagonists have distinct modes of interacting with 5-HT(2A) receptors, complicating efforts at structure-based drug-design. These distinct binding modes would not have been predicted based on conventional structure-activity relationships or static docking models. Fortunately, these complicated binding modes can be predicted and simulated using molecular dynamics, allowing for the possibility of structure-based drug design. Thus, provided appropriately sophisticated drug design strategies are employed, it is likely that uniquely valuable medications will result which could have great potential for treating a variety of mental and physical illnesses.
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PMID:Insights into the structure and function of 5-HT(2) family serotonin receptors reveal novel strategies for therapeutic target development. 1254 Feb 78


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