Clozapine and weight gain

Combining Therapeutic Drug Monitoring and Pharmacokinetic Modelling Deconvolutes Physiological and Environmental Sources of Variability in Clozapine Exposure

Background: Clozapine is a key antipsychotic drug for treatment-resistant schizophrenia but exhibits highly variable pharmacokinetics and a propensity for serious adverse effects. Currently, these challenges are addressed using therapeutic drug monitoring (TDM). This study primarily sought to (i) verify the importance of covariates identified in a prior clozapine population pharmacokinetic (popPK) model in the absence of environmental covariates using physiologically based pharmacokinetic (PBPK) modelling, and then to (ii) evaluate the performance of the popPK model as an adjunct or alternative to TDM-guided dosing in an active TDM population. Methods: A popPK model incorporating age, metabolic activity, sex, smoking status and weight was applied to predict clozapine trough concentrations (C_min) in a PBPK-simulated population and an active TDM population comprising 142 patients dosed to steady state at Flinders Medical Centre in Adelaide, South Australia. Post hoc analyses were performed to deconvolute the impact of physiological and environmental covariates in the TDM population. Results: Analysis of PBPK simulations confirmed age, cytochrome P450 1A2 activity, sex and weight as physiological covariates associated with variability in clozapine C_min (R² = 0.7698; p = 0.0002). Prediction of clozapine C_min using a popPK model based on these covariates accounted for <5% of inter-individual variability in the TDM population. Post hoc analyses confirmed that environmental covariates accounted for a greater proportion of the variability in clozapine C_min in the TDM population. Conclusions: Variability in clozapine exposure was primarily driven by environmental covariates in an active TDM population. Pharmacokinetic modelling can be used as an adjunct to TDM to deconvolute sources of variability in clozapine exposure.

Clozapine Pharmacogenetic Studies in Schizophrenia: Efficacy and Agranulocytosis

Clozapine is an efficacious atypical antipsychotic for treatment-refractory schizophrenia. Clinical response and appearance of adverse events vary among individual patients receiving clozapine, with genetic and non-genetic factors potentially contributing to individual variabilities. Pharmacogenetic studies investigate associations between genetic variants and drug efficacy and toxicity. To date, most pharmacogenetic studies of clozapine have been conducted through candidate gene approaches. A recent advance in technology made it possible to perform comprehensive genetic mapping underlying clinical phenotypes and outcomes, which allow novel findings beyond biological hypotheses based on current knowledge. In this paper, we will summarize the studies on clozapine pharmacogenetics that have extensively examined clinical response and agranulocytosis. While there is still limited evidence on clozapine efficacy, recent genome-wide studies provide further evidence of the involvement of the human leukocyte antigen (HLA) region in clozapine-induced agranulocytosis.

[Pharmacogenetic-based risk assessment of antipsychotic-induced extrapyramidal symptoms]

"Typical" antipsychotics remain the wide-prescribed drugs in modern psychiatry. But these drugs are associated with development of extrapyramidal symptoms (EPS). Preventive methods of EPS are actively developed and they concentrate on personalized approach. The method of taking into account genetic characteristics of patient for prescribing of treatment was proven as effective in cardiology, oncology, HIV-medicine. In this review the modern state of pharmacogenetic research of antipsychotic-induced EPS are considered. There are pharmacokinetic and pharmacodynamic factors which impact on adverse effects. Pharmacokinetic factors are the most well-studied to date, these include genetic polymorphisms of genes of cytochrome P450. However, evidence base while does not allow to do the significant prognosis of development of EPS based on genetic testing of CYP2D6 and CYP7A2 polymorphisms. Genes of pharmacodynamics factors, which realize the EPS during antipsychotic treatment, are the wide field for research. In separate part of review research of such systems as dopaminergic, serotonergic, adrenergic, glutamatergic, GABAergic, BDNF were analyzed. The role of oxidative stress factors in the pathogenesis of antipsychotic-induced EPS was enough detailed considered. The system of those factors may be used for personalized risk assessment of antipsychotics' safety in the future. Although there were numerous studies, the pharmacogenetic-based prevention of EPS before prescribing of antipsychotics was not introduced. However, it is possible to distinguish the most perspectives markers for further research. Furthermore, brief review of new candidate genes provides here, but only preliminary results were published. The main problem of the field is the lack of high- quality studies. Moreover, the several results were not replicated in repeat studies. The pharmacogenetic-based research must be standardized by ethnicity of patients. But there is the ethnical misbalance in world literature. These facts explain why the introduction of pharmacogenetic testing for risk assessment of antipsychotic-induced EPS is so difficult to achieve.

Eating disorders and psychosis: Seven hypotheses

Psychotic disorders and eating disorders sometimes occur in the same person, and sometimes, but not always, at the same time. This can cause diagnostic confusion and uncertainty about treatment. This paper examines seven ways in which symptoms of both conditions can co-exist. The literature on this topic consists to a large extent of case reports, so that firm conclusions cannot be drawn from their examination. There is no consistent sequence in the co-occurrence of the two conditions-eating disorders sometimes precede, and sometimes follow the onset of psychosis. The advent of the psychosis, and sometimes the treatment of the psychosis can cure the eating disorder, but it can sometimes aggravate it. Psychosis is not necessarily a mark of severity in the course of an eating disorder, and food refusal can occur independent of severity in psychotic illness, but it can be a cause of death. There is some genetic association and some overlap of physiologic, cognitive and brain structure deficits in the two types of disorder. The connection between the two, however, remains speculative. The area of comorbidity and overlapping symptoms in psychiatry requires more research. Clinical recommendations include attention to the different individual ways in which these two disparate conditions often overlap.

Smoking and weight among patients using clozapine

BACKGROUND

Both obesity and smoking are common in schizophrenia patients taking clozapine, causing cardiovascular disease and premature deaths.

METHODS

Two hundred and thirty-seven patients with schizophrenia or related psychoses treated with clozapine completed the Liverpool University Neuroleptic Assessment Scale (LUNSERS) and a questionnaire including current height, weight, changes therein and smoking status.

AIMS

The aim of this study was to analyze weight and weight change in smoking and non-smoking patients taking clozapine. A possible interaction between obesity and smoking was explored.

RESULTS

No association was found between weight change and smoking status during clozapine treatment. There was no significant difference in body mass index (BMI) between non-smokers and smokers. In the analysis of covariance (ANCOVA) with BMI as the dependent variable, the best fitting model comprised age, sex, intensity of sedation, and reported amount of smoking as explanatory variables (ηp(2)= 0.116; P = 0.029; power = 0.750). None of the explanatory proportions of any single factor was significant.

CONCLUSIONS

Estimated according to reported weight gain and BMI, no difference was found between smoking and non-smoking clozapine-treated patients. Number of cigarettes smoked explained BMI if age and sex were taken into account. This result is in line with the findings of some general population studies, where heavy smoking has been associated with a greater risk of obesity.

Pharmacogenetics of antipsychotics

OBJECTIVE

During the past decades, increasing efforts have been invested in studies to unravel the influence of genetic factors on antipsychotic (AP) dosage, treatment response, and occurrence of adverse effects. These studies aimed to improve clinical care by predicting outcome of treatment with APs and thus allowing for individualized treatment strategies. We highlight most important findings obtained through both candidate gene and genome-wide association studies, including pharmacokinetic and pharmacodynamic factors.

METHODS

We reviewed studies on pharmacogenetics of AP response and adverse effects published on PubMed until early 2012. Owing to the high number of published studies, we focused our review on findings that have been replicated in independent studies or are supported by meta-analyses.

RESULTS

Most robust findings were reported for associations between polymorphisms of the cytochrome P450 system, the dopamine and the serotonin transmitter systems, and dosage, treatment response, and adverse effects, such as AP-induced weight gain or tardive dyskinesia. These associations were either detected for specific medications or for classes of APs.

CONCLUSION

First promising and robust results show that pharmacogenetics bear promise for a widespread use in future clinical practice. This will likely be achieved by developing algorithms that will include many genetic variants. However, further investigation is warranted to replicate and validate previous findings, as well as to identify new genetic variants involved in AP response and for replication of existing findings.

Psychotropic drug prescribing in an Australian specialist child and adolescent eating disorder service: a retrospective study

BACKGROUND

To describe the rates, indications, and adverse effects of psychotropic drug prescription in a specialist tertiary hospital child and adolescent eating disorder service.

METHODS

Retrospective case note study of all active eating disorder patients (N = 115) over the period of treatment from referral to time of study (M = 2 years), covering patient demographics, clinical characteristics, drug prescriptions, indications, and adverse effects.

RESULTS

Psychotropic drugs were prescribed in 45% of cases, most commonly antidepressants (41%), followed by anxiolytics (29%) and antipsychotics (22%), with 8% initiated before referral to the specialist eating disorder program. Common indications were depressed mood, agitation, anxiety, and insomnia. Patient clinical severity and complexity was associated with prescribing. Adverse effects, mostly minor, were recorded in 23% of antidepressant prescriptions, 39% of antipsychotic prescriptions, and 13% of anxiolytic prescriptions. Second generation antipsychotic prescription was associated with subsequent new onset binge eating, in this preliminary observational study. Self-harm by overdose of psychotropics occurred in 11% of patients prescribed medication.

CONCLUSIONS

Psychotropic medications were frequently prescribed to adolescent eating disorder patients to treat distressing symptoms. Prospective randomised controlled trials to clarify efficacy and safety are needed. Given the difficulties of conducting clinical trials in this population, services are encouraged to monitor and audit medication safety and efficacy in everyday practice, and to report their findings.

Weight Change in Monozygotic Twins Treated with Valproate

OBJECTIVE

To evaluate whether genetic factors contribute to weight gain associated with valproate (VPA) therapy.

RESEARCH METHODS AND PROCEDURES

We retrospectively and prospectively evaluated five pairs of monozygotic twins concordant for epilepsy and treated with VPA regarding weight course.

RESULTS

In all twin pairs, both twins showed similar weight courses under therapy with VPA.

DISCUSSION

These results suggest that genetic factors may have an influence on the weight change induced by VPA. Further studies are necessary to obtain heritability estimates regarding this effect of VPA therapy and to identify the relevant genes.

Subjective and Biological Weight-Related Parameters

Objective: Administration of atypical antipsychotics often induces significant weight gain and metabolic changes. Little is known about subjective weight-related parameters in adolescent patients. Therefore, this cross-sectional, explorative study aimed to assess these parameters and their relationship with biological weight-related parameters. Method: 74 patients (mean age: 19.9 [SD ± 2.3] years; 66.2% male) with schizophrenia under clozapine or olanzapine treatment were examined. Subjective well-being, eating behavior, body perception and social functioning were assessed, using the Three-Factor-Eating-Questionnaire, FKB-20 Body Perception Questionnaire, Subjective Well-being under Neuroleptics, Short Form and Global Assessment of Functioning. Patients’ biological weight-related parameters were measured as well. Gender differences as well as associations between subjective and biological weight-related parameters were evaluated. Results: Female patients reported significantly worse negative body appraisal and physical functioning than males. An elevated BMI was associated with impaired physical functioning in females and with negative body appraisal and hunger in males. Conclusions: In our sample of young patients with schizophrenia unter treatment with atypical antipsychotics, an elevated BMI was associated with impaired physical functioning and negative body appraisal, respectively. Bearing in mind the high risk of obesity in this population, the mentioned impairments should be accounted for, especially in terms of compliance and quality of life.

Weight-reducing side effects of the antiepileptic agents topiramate and zonisamide

Drug-induced weight alteration can be a serious side effect that applies to several therapeutic agents and must be referred to in the respective approved labeling texts. The side effect may become health threatening in case of significant weight change in either direction. Several antiepileptic drugs (AEDs) are associated with weight gain such as gabapentin, pregabalin, valproic acid, and vigabatrin and to some extent carbamazepine. Others are weight neutral such as lamotrigine, levetiracetam, and phenytoin or associated with slight weight loss as, e.g., felbamate. The focus of this chapter is on the two AEDs causing strong weight loss: topiramate and zonisamide. For both drugs, several molecular mechanisms of actions are published. We provide a review of these potential mechanisms, some of which are based on in vivo studies in animal models for obesity, and of clinical studies exploring these two drugs as single entities or in combinations with other agents.

Eating disorders and schizophrenia in male patients: a review

OBJECTIVE

To understand the comorbidity of schizophrenia and eating disorders (ED) in male patients.

METHOD

A review of the published literature was made via Med- Line using the following terms: "schizophrenia" or "psychosis" in association with "eating disorders", "anorexia nervosa", "binge eating" or "bulimia nervosa", in association with the terms "comorbidity" or "comorbidities" and finally in association with the term "male", "man" or "men".

RESULTS

Groups of male patients known to suffer from schizophrenia and screened for ED suffer essentially from anorexia nervosa (0.81%). Groups of male patients screened for anorexia nervosa and then for schizophrenia demonstrate high comorbidity prevalence (36%). In general, ED symptoms diminish with psychotic episodes and recur when the psychotic episode remits. A man with an ED has a 3.6 times more risk than a woman with an ED to have comorbid schizophrenia. In men, ED present atypical features so that ED not otherwise specified (EDNOS) is relatively frequent.

DISCUSSION AND CONCLUSION

Male patients described in the literature as suffering from schizophrenia and ED fall under one of four categories: a) acute psychotic episode related to organic causes due to malnutrition; b) male patients presenting with an ED who later develops schizophrenia; c) male patients known to suffer from schizophrenia and who develops distorted eating cognitions and disordered behaviors; d) male patients suffering from schizophrenia and developing a medication-induced ED.

Carbohydrate reward and psychosis: an explanation for neuroleptic induced weight gain and path to improved mental health?

Evidence links dopamine release in the mid-brain to the pathophysiology of psychosis, addiction and reward. Repeated ingestion of refined carbohydrate may stimulate the same mesolimbic dopaminergic pathway, rewarding such eating behaviour and resulting in excessive food intake along with obesity. In this paper, we explore the role of dopamine in reward and psychosis, and discuss how reward pathways may contribute to the weight gain that commonly follows antipsychotic drug use, in people with psychotic illness. Our theory also explains the frequent co-occurrence of substance abuse and psychosis. From our hypothesis, we discuss the use of carbohydrate modified diets as an adjunctive treatment for people with psychosis.

Increased food intake and energy expenditure following administration of olanzapine to healthy men

Atypical antipsychotic medications like olanzapine (OLZ) induce weight gain and increase the risk of diabetes in patients with schizophrenia. The goal of this study was to assess potential mechanisms of OLZ-induced weight gain and accompanying metabolic effects. Healthy, lean, male volunteers received OLZ and placebo (PBO) in a randomized, double-blind, crossover study. In periods 1 and 2, subjects received OLZ (5 mg for 3 days then OLZ 10 mg for 12 days) or matching PBO separated by a minimum 12-day washout. Twenty-four hour food intake (FI), resting energy expenditure (REE), activity level, metabolic markers, and insulin sensitivity (IS) were assessed. In total, 30 subjects were enrolled and 21 completed both periods. Mean age and BMI were 27 years (range: 18-49 years) and 22.6 +/- 2.2 kg/m(2), respectively. Relative to PBO, OLZ resulted in a 2.62 vs. 0.08 kg increase in body weight (P < 0.001) and 18% (P = 0.052 or 345 kcal) increase in FI. Excluding one subject with nausea and dizziness on the day of OLZ FI measurement, the increase in FI was 547 kcal, (P < 0.05). OLZ increased REE relative to PBO (113 kcal/day, P = 0.003). Significant increases in triglycerides, plasminogen activator inhibitor-I (PAI-I), leptin, and tumor necrosis factor-alpha (TNF-alpha) were observed. No significant differences in activity level or IS were observed. This study provides evidence that OLZ pharmacology drives the early increase in weight through increased FI, without evidence of decreased energy expenditure (EE), activity level, or short-term perturbations in IS.

Acute clozapine exposure in vivo induces lipid accumulation and marked sequential changes in the expression of SREBP, PPAR, and LXR target genes in rat liver

BACKGROUND

Several antipsychotic drugs (APDs) have high propensity to induce weight gain and dyslipidemia in patients, with clozapine and olanzapine as the most potent drugs. These lipid-related effects have been attributed to drug-mediated blockade or antagonism of histamine H1 and serotonin 5-HT2 receptors as well as activation of hypothalamic AMP-activated protein kinase. We recently showed that APDs activate lipid biosynthesis in cultured liver cells through stimulation of the sterol regulatory element-binding protein (SREBP) transcription factors.

OBJECTIVE

The objective of the study was to search for clozapine-related lipogenic effects in peripheral tissues in vivo using rat liver as target organ.

MATERIALS AND METHODS

Adult female Sprague-Dawley rats were administered single intraperitoneal injections of clozapine (25 and 50 mg/kg). Hepatic lipid levels were measured during a 48-h time course. Real-time quantitative PCR was used to analyze expression of genes involved in lipid biosynthesis, oxidation, efflux, and lipolysis.

RESULTS

We identified an initial up-regulation of central lipogenic SREBP target genes, followed by a marked and sustained down-regulation. We also observed a sequential transcriptional response for fatty acid beta-oxidation and cholesterol efflux genes, normally controlled by the peroxisome proliferator activated receptor alpha and liver X receptor alpha transcription factors, and also down-regulation of genes encoding major lipases. The transcriptional responses were associated with a significant accumulation of triacylglycerol, phospholipids, and cholesterol in the liver.

CONCLUSION

These results demonstrate that acute clozapine exposure affects SREBP-regulated lipid biosynthesis as well as other lipid homeostasis pathways. We suggest that such drug-induced effects on lipid metabolism in peripheral tissues are relevant for the metabolic adverse effects associated with clozapine and possibly other APDs.

Possible association between the -2548A/G polymorphism of the leptin gene and olanzapine-induced weight gain

Antipsychotic-induced weight gain has important effects on treatment compliance and long-term health. Several reports have indicated that a -2548A/G single-nucleotide polymorphism (SNP) of the leptin gene is associated with antipsychotic-induced weight gain. We hypothesized that there is a similar relationship between the -2548A/G SNP and olanzapine-induced weight gain. A total of 74 Korean schizophrenic patients were examined. Their weight was measured before starting olanzapine and after long-term treatment lasting for at least 3 months. The weight gain was significantly higher for patients with the AG genotype than for those with the AA genotype (p=0.029). Analysis of covariance also showed the difference of weight gain was still significant when adjusted for sex and treatment duration (p=0.046). This finding supports the presence of a relationship between the -2548A/G SNP of the leptin gene and weight gain in Korean schizophrenic patients receiving olanzapine treatment.

Clozapine/olanzapine-induced recurrence or deterioration of binge eating-related eating disorders

OBJECTIVE

To explore the association between eating disorders (EDs) prior to the use of clozapine/olanzapine (pre-clozapine/olanzapine EDs) and after initiation of these antipsychotics (post-clozapine/olanzapine EDs).

METHOD

Sixty-four consecutively admitted patients receiving clozapine/olanzapine were screened using the M-Composite International Diagnostic Interview (M-CIDI) to identify subjects with pre-clozapine/olanzapine EDs (DSM-IV criteria). We investigated post-clozapine/olanzapine EDs and binge eating behavior using the Questionnaire on Eating and Weight Patterns (QEWP) and used the Naranjo probability scale as objective causality assessment.

RESULTS

Post-clozapine/olanzapine EDs were significantly more frequent in patients with pre-clozapine/olanzapine EDs (5 of 6) when compared to patients without pre-clozapine/olanzapine EDs (4 of 58) [chi(2) = 26.29; df = 1; p < 0.001] [odds ratio (OR) 67.5; 95% CI: 6.3-725.8]. According to the Naranjo probability scale, recurrence or deterioration of EDs in patients with prior EDs was definitely (n = 1) or probably (n = 4) related to the intake of clozapine/olanzapine.

CONCLUSION

Clozapine/olanzapine may induce recurrence or deterioration of binge eating symptomatology or full-blown EDs in patients with prior EDs.

Genetics of antipsychotic treatment emergent weight gain in schizophrenia

Classic and modern antipsychotics can induce substantial weight gain causing diabetes, lipid abnormalities and psychological distress. Treatment emergent weight gain varies within the broad class of antipsychotics; however, an individual's propensity to develop weight gain largely depends on genetic factors. The first part of this review highlights current ideas and concepts related to antipsychotic-induced weight gain, including principles on energy homeostasis. The second part summarizes genetic findings emphasizing studies published after 2003 as prior studies have been reviewed in detail elsewhere. Candidate gene studies have produced significant findings in the 5-hydroxytryptamin 2C (5HT2C) and adrenergic alpha2a (ADRalpha2a) receptor genes, as well as in the leptin, guanine nucleotide binding protein (GNB3) and synaptomal-associated protein 25kDa (SNAP25) genes. Results from genome-wide association and linkage studies point to several chromosomal regions (e.g., 12q24) and some specific genes (e.g., promelanin concentrating hormone [PMCH], polycyctic kidney and hepatic disease 1 [PKHD1], peptidylglycine alpha-amidating monooxygenase [PAM]). However, more efforts are needed before risk prediction and personalized medicine can be made available for antipsychotic-induced weight gain.

No evidence for binding of clozapine, olanzapine and/or haloperidol to selected receptors involved in body weight regulation

The underlying mechanisms of antipsychotic (AP)-induced weight gain are unknown, but both central and peripheral AP target receptors could potentially be involved. This study used radioligand binding assays to compare the binding affinities of clozapine, olanzapine and haloperidol for candidate receptors potentially involved in AP-induced weight gain. Selected candidates derived from known pathways involved in body weight regulation included receptors classified as anorexigenic (bombesin receptor subtype 3, calcitonin gene-related peptide receptor, cholecystokinin receptor, melanocortin-4 receptor, neurotensin receptor 1) or orexigenic (cannabinoid receptor 1, galanin 1 receptor, melanin-concentrating hormone receptor (MCHR), neuropeptide Y1 receptor) as well as receptors involved in physiological actions related to digestion and fluid homeostasis (angiotensin II type 1 receptor, bradykinin B2 receptor, endothelin receptor, neurokinin 1 receptor, vasoactive intestinal polypeptide receptor 1). Clozapine, olanzapine and haloperidol exhibited negligible affinities to all of these receptors except for the MCHR (Ki=501 nM; haloperidol). With respect to other candidates from (neuro)transmitter systems already suggested to be involved in AP-induced weight gain, the binding profile of olanzapine resembled that of clozapine, with high affinity (Ki<10 nM) for serotonin (5-HT) 5-HT2A, 5-HT2C and 5-HT6, muscarinic M1 and histamine H1 receptors. In contrast, the binding profile of haloperidol was substantially different (high affinity only for the dopamine D1 receptor). In conclusion, we have not identified a novel binding site of the two investigated atypical AP that could contribute to the induced weight gain.

Clozapine-induced weight gain: a study in monozygotic twins and same-sex sib pairs

To assess the relative contribution of genetic factors in antipsychotic-induced weight gain, we explored the similarity in body mass index (BMI) (kg/m(2)) change under clozapine only (clozapine DeltaBMI) and upon additional inclusion of BMI change under prior antipsychotic medication (total DeltaBMI) of five monozygotic twins in comparison with seven same-sex sibs. Twin and sib pairs were identified by a telephone screening of 786 office-based psychiatrists. Measured data on weight and other clinical variables were obtained cross-sectionally and retrospectively from medical records. We found greater similarity in total DeltaBMI in monozygotic twins (intrapair difference 2.78+/-3.41 kg/m(2)) than in same-sex sibs (5.55+/-4.35 kg/m(2)), resulting in heritability estimates of h(2)=0.8 and A=0.45 (ACE twin model). However, intrapair differences in clozapine DeltaBMI were similar between twins (4.18+/-4.27 kg/m(2)) and sibs (4.68+/-4.88 kg/m(2)). We hypothesize that the weight plateau achieved under clozapine is influenced by genetic factors. The weight gain achieved during pretreatment with other antipsychotics seems to limit clozapine-induced weight gain, thus presumably explaining why heritability/similarity in monozygotic twins in comparison with same-sex sibs is greater for total DeltaBMI than for clozapine DeltaBMI. An important caveat is that, owing to the sample size, the heritability estimates have a large standard error and thus have to be interpreted with caution.

Modern antipsychotic drugs: a critical overview

Conventional antipsychotic drugs, used for a half century to treat a range of major psychiatric disorders, are being replaced in clinical practice by modern "atypical" antipsychotics, including aripiprazole, clozapine, olanzapine, quetiapine, risperidone and ziprasidone among others. As a class, the newer drugs have been promoted as being broadly clinically superior, but the evidence for this is problematic. In this brief critical overview, we consider the pharmacology, therapeutic effectiveness, tolerability, adverse effects and costs of individual modern agents versus older antipsychotic drugs. Because of typically minor differences between agents in clinical effectiveness and tolerability, and because of growing concerns about potential adverse long-term health consequences of some modern agents, it is reasonable to consider both older and newer drugs for clinical use, and it is important to inform patients of relative benefits, risks and costs of specific choices.

Prise de poids pharmaco-induite par les psychotropes et sa prise en charge : revue des données de la littérature

Weight gain is associated with the use of many psychotropic medications, including antidepressants, mood stabilizers, antipsychotic drugs, and may have serious long term consequences: it can increase health risks, specifically from overweight (BMI = 25-29.9 kg/m2) to obesity (BMI > or =30 kg/m2), according to Body Mass Index (BMI), and the morbidity associated therewith in a substantial part of patients (hypertension, coronary heart desease, ischemic stroke, impaired glucose tolerance, diabetes mellitus, dyslipidemia, respiratory problems, osteoarthritis, cancer); according to patients, psychosocial consequences such as a sense of demoralization, physical discomfort and being the target of substantial social stigma are so intolerable that they may discontinue the treatment even if it is effective. The paper reviews actual epidemiological data concerning drug induced weight gain and associated health problems in psychiatric patients : there is a high risk of overweight, obesity, impaired glucose tolerance, diabetes mellitus, premature death, in patients with schizophrenia or bipolar disorder; and the effects of specific drugs on body weight: Tricyclic Antidepressants (TCA) induced weight gain correlated positively with dosage and duration of treatment, more pronounced with amitriptyline ; Selective Serotonin Reuptake Inhibitors (SSRI) decrease transiently bodyweight during the first few weeks of treatment and may then increase bodyweight; weight gain appears to be most prominent with some mood stabilizers (lithium, valproate); atypical antipsychotics tend to cause more weight gain than conventional ones and weight gain, diabetes, dyslipidemia, seem to be most severe with clozapine and olanzapine. Conceming the underlying mechanisms of drug induced weight gain, medications might interfere with central nervous functions regulating energy balance; patients report about: increase of appetite for sweet and fatty foods or "food craving" (antidepressants, mood stabilizers, antipsychotic drugs) and weight gain despite reduced appetite which can be explained by an altered resting metabolic rate (TCA, SSRI, Monoaminoxidase Inhibitors MAO I). According to current concepts, appetite and feeding are regulated by a complex of neurotransmitters, neuromodulators, cytokines and hormones interacting with the hypothalamus, including the leptin and the tumor necrosis factor system. The pharmacologic mechanisms underlying weight gain are presently poorly understood: maybe the different activities at some receptor systems may induce it, but also genetic predisposition. Understanding of the metabolic consequences of psychotropic drugs (weight gain, diabetes, dyslipidemia) is essential: the insulin-like effect of lithium is known; treatment with antipsychotic medications increases the risk of impaired glucose tolerance and diabetes mellitus. Several management options of weight gain are available from choosing or switching to another drug, dietary advices, increasing physical activities, behavioural treatment, but the best approach seems to attempt to prevent the weight gain : patients beginning maintenance therapy should be informed of that risk, and nutritional assessment and counselling should be a routine part of treatment management, associated with monitoring of weight, BMI, blood pressure, biological parameters (baseline and three months monitoring of fasting glucose level, fasting cholesterol and triglyceride levels, glycosylated haemoglobin). Psychiatrics must pay attention to concomitant medications and individual factors underlying overweight and obesity. Weight gain has been described since the discovery and the use of the firstpsychotropic drugs, but seems to intensify with especially some of the second generation antipsychotic medications ; understanding of the side effects of psychotropic drugs, including their metabolic consequences (weight gain, diabetes, dyslipidemia) is essential for the psychiatrics to avoid on the one hand a risk of lack of compliance, a discontinuation of the pharmacological medication and also a risk of relapse and rehospitalization, and on the other hand to avoid acute life threatening events (diabetic ketoacidocetosis and non ketotic hyperosmolar coma, long term risk complications of diabetes and overweight).

A prospective study of serum ghrelin levels in patients treated with clozapine

We investigated serum ghrelin levels (SGL) in 12 patients with schizophrenia over a 10-week period after initiation of clozapine treatment. In contrast to increments of body mass indices (BMI, kg/m2) and serum leptin levels (SLL), no significant change in SGL was detected. Inverse correlations between delta SGL and delta SLL did not reach statistical significance. Linear mixed model analysis could not detect effects of age, sex, BMI, SLL and serum clozapine levels on SGL. Our results do not support a causal involvement of ghrelin in clozapine-related weight gain.

Clozapine: weight gain in a pair of monozygotic twins concordant for schizophrenia and mild mental retardation

Clozapine is an atypical antipsychotic known to cause considerable weight gain. The extent to which genetic factors determine weight gain is unknown. Here we report on a pair of female monozygotic twins concordant for schizophrenia and mild mental retardation who were treated with clozapine over 5.5 years. One twin gained a total of 53.1 kg and had a weight of 107.5 kg (BMI=38.1 kg/m2) at the end of the observation period. The other twin gained a total of 48.2 kg and finally had a weight of 100.4 kg (BMI=33.8 kg/m2). Because both patients experienced considerable weight gain during treatment, our observation suggests that the antipsychotic-induced weight gain is under strong genetic control.

Lack of association between the –759C/T polymorphism of the 5-HT2C receptor gene and clozapine-induced weight gain among German schizophrenic individuals

Weight gain is a major side effect of treatment with clozapine and other antipsychotics. Recent studies suggest an important role of the serotonin type 2C receptor gene (5-HT2CR) in antipsychotic-induced weight gain. However, investigations pertaining to a possible association between a -759C/T polymorphism (C allele) of the 5-HT2CR and weight gain induced by clozapine and/or other antipsychotics have yielded inconsistent results. We investigated the -759C/T polymorphism of the 5-HT2CR in relation to clozapine-induced change in body mass index (BMI) (kg/m) in 97 German patients with schizophrenia and found no association between the -759C allele and weight gain after 12 weeks of clozapine treatment. In addition, confounding effects of initial BMI, age, sex and duration of illness on change in BMI could not be detected by multiple linear regression analysis. Our data do not support an involvement of the -759C/T polymorphism of the 5-HT2CR in clozapine-induced weight gain in German patients with schizophrenia. Further pharmacogenetic studies pertaining to antipsychotic-induced weight gain are warranted.

Epidemiology, implications and mechanisms underlying drug-induced weight gain in psychiatric patients

Body weight gain frequently occurs during drug treatment of psychiatric disorders and is often accompanied by increased appetite or food craving. While occurrence and time course of this side effect are difficult to predict, it ultimately results in obesity and the morbidity associated therewith in a substantial part of patients, often causing them to discontinue treatment even if it is effective. This paper reviews the available epidemiological data on the frequency and extent of weight gain associated with antidepressant, mood-stabilizing, and antipsychotic treatment. Possible underlying pathomechanisms are discussed with special attention to central nervous control of appetite including the role of leptin and the tumor necrosis factor system. Metabolic alterations induced by drug treatment such as type 2 diabetes mellitus and the metabolic syndrome are also considered. Weight gain appears to be most prominent in patients treated with some of the second generation antipsychotic drugs and with some mood stabilizers. Marked weight gain also frequently occurs during treatment with most tricyclic antidepressants, while conventional antipsychotics typically induce only slight to moderate weight gain. Serotonin reuptake inhibitors may induce weight loss during the first few weeks, but some of them induce weight gain during long-term treatment. Several antidepressant and antipsychotic drugs are identified which reliably do not cause weight gain or even reduce weight. Based on these insights, countermeasures to manage drug-induced weight gain are suggested.