Adverse Metabolic Effects Associated with Atypical Antipsychotics

Inhibitory effects of antipsychotics on carbachol-enhanced insulin secretion from perifused rat islets: role of muscarinic antagonism in antipsychotic-induced diabetes and hyperglycemia

Treatment with the atypical antipsychotics olanzapine and clozapine has been associated with an increased risk for deterioration of glucose homeostasis, leading to hyperglycemia, ketoacidosis, and diabetes, in some cases independent of weight gain. Because these events may be a consequence of their ability to directly alter insulin secretion from pancreatic beta-cells, we determined the effects of several antipsychotics on cholinergic- and glucose-stimulated insulin secretion from isolated rat islets. At concentrations encompassing therapeutically relevant levels, olanzapine and clozapine reduced insulin secretion stimulated by 10 micromol/l carbachol plus 7 mmol/l glucose. This inhibition of insulin secretion was paralleled by significant reductions in carbachol-potentiated inositol phosphate accumulation. In contrast, risperidone or ziprasidone had no adverse effect on cholinergic-induced insulin secretion or inositol phosphate accumulation. None of the compounds tested impaired the islet secretory responses to 8 mmol/l glucose alone. Finally, in vitro binding and functional data show that olanzapine and clozapine (unlike risperidone, ziprasidone, and haloperidol) are potent muscarinic M3 antagonists. These findings demonstrate that low concentrations of olanzapine and clozapine can markedly and selectively impair cholinergic-stimulated insulin secretion by blocking muscarinic M3 receptors, which could be one of the contributing factors to their higher risk for producing hyperglycemia and diabetes in humans.

Plasma levels of leptin and endogenous immune modulators during treatment with carbamazepine or lithium

Several psychopharmacological agents induce weight gain. Recent studies have suggested that the tumor necrosis factor-alpha (TNF-alpha) cytokine system is pathophysiologically involved. To assess whether carbamazepine and lithium, which have been reported to lead to weight gain, have effects on the circulating levels of cytokines, we measured plasma levels of TNF-alpha, its soluble receptors sTNF-R p55 and p75, and leptin, as well as weight in 25 inpatients receiving lithium (n=10) or carbamazepine (n=15) weekly during the first 4 weeks of treatment. We found an increase in the body mass index and in TNF-alpha and its soluble receptor levels, but not in leptin levels over the 4 weeks of treatment. These changes did not differ between treatment groups. Changes of weight during the first week of treatment, but no other parameter, strongly predicted weight change until endpoint. We conclude that the mood stabilizers carbamazepine and lithium have similar effects on the TNF-alpha system and do not affect leptin levels.

Predictors and markers of clozapine response

RATIONALE

With other atypical antipsychotics now available, having predictors of clozapine response would be of considerable value, offering clinicians guidance in their decision as to when, and if, a trial of clozapine is warranted.

OBJECTIVES

The aim was to review existing evidence regarding identified predictors and markers of clozapine response.

METHODS

Relevant studies were identified through PUBMED searches (1975-June 2004) and cross-referencing of reviews and included studies. The data were summarized under two main categories: clinical (general, neurological, cognitive/neuropsychological, clozapine levels) and biological (biochemical, endocrine, genetic, metabolic, morphological, dopamine D2 receptor occupancy). 'Reliable' predictors/markers were defined a priori as those with support of at least two independent reports that addressed overall response, with no contradictory findings to date. 'Potential' predictors/markers had the support of a single report that addressed overall response and at least one other evaluating treatment outcome but not directly addressing response status.

RESULTS AND CONCLUSIONS

Higher baseline clinical symptoms and functioning in the previous years and low cerebrospinal homovanillic acid/5-hydroxyindoleacetic acid levels were identified as reliable. Three potential measures were identified: reduction of frontal cortex metabolic activity, reduction of caudate volume, and improvement in P50 sensory gating.

The poor general health of the severely mentally ill: impact of schizophrenic diagnosis

This study focused on poor health among the severely mentally ill and additional risks associated with schizophrenia. Records of 781 clients in short-term residential treatment programs provided data. The schizophrenic subgroup was compared to others in bivariate analyses, with significant findings included in logistic regression. Those with schizophrenia were more likely to be male, unemployed, and insured by MediCal/Medicare. Most health problems occurred at similar rates across diagnoses, reflecting common environmental risk factors. Those with schizophrenia had less substance abuse and fewer liver conditions, but more diabetes and chronic respiratory problems. Implications for providers and for research are discussed.

Toxicology and overdose of atypical antipsychotic medications in children: does newer necessarily mean safer?

PURPOSE OF REVIEW

Atypical antipsychotic medications (second-generation antipsychotics) have been increasingly used in the treatment of a number of psychotic disorders since their introduction in 1988, with the newest medication introduced in 2002. Justification for their use includes claims of equal or improved antipsychotic activity over first-generation antipsychotics, increased tolerability, and decreased side effects. However, there are still significant adverse effects and toxicities with this class of medications. Toxicologic exposures and fatalities associated with atypical antipsychotics continue to increase in the United States, with 32,422 exposures and 72 deaths in 2003. There have also been Food and Drug Administration warnings in the past year about how some atypical antipsychotics have been marketed to minimize the potentially fatal risks and claiming superior safety to other atypical antipsychotics without adequate substantiation, indicating the toxicologic potential of these agents may be underestimated.

RECENT FINDINGS

Continued research to evaluate adverse effects and tolerability of atypical antipsychotics compared with first-generation antipsychotics and each other is reviewed. This article also reviews the pharmacodynamics, pharmacokinetics, and drug interactions with these medications. New therapeutic monitoring recommendations for this class of medications have also been proposed. Finally, clinical toxicity in overdose and management are reviewed.

SUMMARY

While new atypical antipsychotic medications may have a safer therapeutic and overdose profile than first-generation antipsychotic medications, many adverse and toxic effects still need to be considered in therapeutic monitoring and overdose management.

Prevalence of obesity, glucose homeostasis disorders and metabolic syndrome in psychiatric patients taking typical or atypical antipsychotic drugs: a cross-sectional study

AIMS/HYPOTHESIS

Atypical antipsychotic drugs may be associated with obesity and other components of the metabolic syndrome, but this relationship is controversial. We investigated the hypothesis that atypical antipsychotics are associated with a greater degree of metabolic dysfunction than typical agents.

METHODS

Metabolic parameters were measured in 103 diagnostically heterogeneous psychiatric out-patients. Patients had been taking typical or atypical antipsychotic drugs for a minimum of six months.

RESULTS

Sixty-nine patients were taking atypical agents, 20 typical agents and 14 a combination. Mean values (+/-SD) for the whole group were: age 43.8 years (11.4); BMI 29.1 kg/m(2) (5.1); W:H ratio 0.88 (0.09). Metabolic parameters, including beta cell function and insulin sensitivity, measured by HOMA, did not differ with regard to the prescribed antipsychotic drug. Six patients had undiagnosed diabetes, six patients had impaired fasting glucose, and eight fulfilled criteria for the metabolic syndrome, all of whom were taking atypical agents (p=0.07 vs typical agents). Subgroup analyses of those taking atypical agents revealed differences in BMI (mean, +/-SD) between olanzapine (27.3 kg/m(2)+/-5.1) and quetiapine (31.9 kg/m(2)+/-5.1), p=0.01, and HbA(1c) (olanzapine, 5.1%+/-0.6 vs quetiapine, 5.6%+/-0.6; p=0.03). Other atypical agents were intermediate with regard to these parameters.

CONCLUSIONS

Obesity, dyslipidaemia and abnormalities of glucose homeostasis are prevalent in this group. Patients taking atypical agents showed a trend towards abnormalities of glucose homeostasis. Prospective studies are needed to explore the precise relationship between antipsychotic drugs, glucose homeostasis, obesity and the metabolic syndrome.

Current prescribing patterns in outpatient child and adolescent psychiatric practice in central New York

OBJECTIVE

The aim of this study was to evaluate current prescribing patterns of outpatient child psychiatrists in central New York.

METHODS

Data were drawn from all active files of 1- to 18-year-olds (n = 1292) at eight outpatient treatment locations in central New York on one day in 2002. Age, race, gender, diagnoses, current medications, and doses were recorded. Data was tabulated and analyzed to discern prescribing frequencies and patterns.

RESULTS

74% (956 of 1292) of all patients received psychotropic medication, and 50% of these patients (478 of 956) received two or more medications. The most commonly prescribed medications were stimulants, antidepressants, antipsychotics, alpha-agonists, and "mood stabilizer" anticonvulsants. The most frequent diagnoses were attention-deficit/hyperactivity disorder, other disruptive behavior disorders, anxiety disorders, and depressive disorders. Of those youths who received an antipsychotic medication, 77% did not have a diagnosis of a psychotic disorder.

CONCLUSIONS

Psychotropic prescribing frequency in outpatient child psychiatry continues to increase, with a substantial majority of youth in psychiatric treatment receiving medication. Stimulants, antidepressants, and antipsychotics have led the way, as in prior studies. Co-prescribing represents a substantial, and growing, proportion of prescribing practice. Antipsychotics are frequently prescribed for nonpsychotic conditions.

Belgian consensus on metabolic problems associated with atypical antipsychotics

A workshop was convened by a panel of psychiatrists, diabetologists and pharmacists from major Belgian hospitals to review the latest information relating to the risks with second-generation antipsychotics (SGA) for the development of metabolic disorders, especially impaired glucose tolerance, diabetes mellitus and dyslipidemia. The panelists sought to formulate recommendations for practising psychiatrists when initiating and maintaining therapy with SGA, and for the switch of SGA or initiation of further treatment if metabolic complications occur. In addition, recommendations for counselling of the patient and for the cooperation between the psychiatrist and the general physician or diabetologist, respectively, were provided.

Guidelines for prevention and treatment of adverse effects of antipsychotic drugs on glucose-insulin homeostasis and lipid metabolism

RATIONALE

With the antipsychotic drugs available today, especially with some of the newer, atypical antipsychotics, metabolic side effects, such as weight gain, diabetes mellitus and lipid abnormalities, have become a complication to the drug therapy that have to be recognized and treated.

OBJECTIVE

The aim of this article is to suggest guidelines for prevention and treatment of adverse effects of antipsychotics on glucose-insulin homeostasis and lipid metabolism, whereas strategies for management of antipsychotic-induced weight gain are summarized elsewhere.

METHOD

The guidelines are based on results of experimental and clinical studies presented in the article, as well as on a recently published review of 180 articles in the field.

RESULTS

Both conventional and atypical antipsychotics can indirectly, by causing obesity, promote development of insulin resistance and type-2 diabetes. In addition, some atypical agents probably directly induce hyperinsulinemia, followed by weight gain, insulin resistance and drug-induced, sometimes insulin-dependent, diabetes.

CONCLUSION

In this article, guidelines for the management of adverse metabolic effects of antipsychotics are described.

Clinical utilization of atypical antipsychotics in pregnancy and lactation

OBJECTIVE

To analyze the available literature regarding the safety of atypical antipsychotics in pregnancy and lactation in order to recommend evidence-based strategies for pharmacologic management of psychosis in these conditions.

DATA SOURCES

We summarized the results from articles identified via MEDLINE/PubMed/TOXNET (1993-January 31, 2004), using the key terms pregnancy, lactation, breast-feeding, human milk, psychotropic drugs, atypical antipsychotics, olanzapine, quetiapine, risperidone, clozapine, ziprasidone, and aripiprazole.

STUDY SELECTION AND DATA EXTRACTION

Retrospective studies, clinical observations, and case reports regarding the 6 atypical antipsychotics mentioned above were selected and analyzed. Extensive manual review of pertinent journals and textbooks was also performed.

DATA SYNTHESIS

Reviewed studies show that olanzapine and clozapine apparently do not increase the teratogenic risk if administered to pregnant women, while evidence on quetiapine, risperidone, aripiprazole, and ziprasidone is still limited. In contrast, available information is not able to exclude unwanted serious effects associated with the use of all atypical antipsychotics on mother-infant dyads. Furthermore, more than a few studies suggest increased hyperglycemic risk for pregnant women related to atypical antipsychotic therapy during gestation. Finally, published evidence about the effects on long-term infant neurodevelopment of drug exposure through both placenta and breast milk is represented only by sporadic case reports.

CONCLUSIONS

It is well known that potential consequences of an untreated psychotic episode may be severe and may lead to the mother attempting suicide and/or infanticide. For these reasons, clinicians need to help mothers weigh both fetal and neonatal risks of exposure to drugs against the potential risk they and their infant may incur if the psychiatric illness is not treated. On the other hand, atypical antipsychotics in pregnancy and breast-feeding do not show evident advantages in safety when compared with typical neuroleptic agents. Therefore, we suggest that the most relevant parameters for selecting the best clinical option for pregnant and breast-feeding women with schizophrenia and related disorders remain strongly related to 3 main points: (1). cautious evaluation of the risk/benefit ratio of fetal and neonatal drug exposure, (2). degree of severity of maternal psychiatric illness, and (3). careful preliminary choice of drugs characterized by a balanced safety/efficacy profile.