Nursing care of clients treated with atypical antipsychotics who have a risk of developing metabolic instability and/or type 2 diabetes

Objective : The aim of this article is to present a current discussion related to the nursing care of clients treated with atypical antipsychotic medicines and who have a risk of developing metabolic instability and/or Type 2 diabetes. The importance of such a discussion is to provide both the novice and the experienced nurse with additional knowledge of this current health issue with which to inform their nursing practice.

Discussion : The potential for psychosis to be a chronic condition is very high, and often people require antipsychotic medicine for lengthy periods throughout their lives. Sometimes, treatment is for life. The second generation of antipsychotic medicines was greeted with much enthusiasm since it was better tolerated than the first generation. However, each medication has desired and adverse effects and, when taken for lengthy periods, these effects may produce physical illness. Studies show that the prevalence of Type 2 diabetes and the metabolic syndrome was significantly higher in clients with a chronic psychiatric disorder, particularly schizophrenia.

Conclusions : Metabolic instability, especially weight gain, is associated with some psychotropic medicines. Nursing interventions need to include care assessment, planning, intervention, and evaluation for clients treated with antipsychotic medicines in terms of risk minimization strategies in routine nursing care.

Efficacy of atypical antipsychotics in bipolar disorder

Bipolar disorder is a severe and recurrent disorder. Atypical antipsychotics have emerged as both an alternative and adjunct to conventional mood stabilisers. The manic phase of the illness is the best studied, and it appears that a class effect with regards to efficacy is present in both monotherapy and augmentation studies. Evidence for efficacy of atypical antipsychotics in depression is emerging. At this stage controlled data are available for both olanzapine and quetiapine. Maintenance data demonstrating efficacy are available for olanzapine. Atypical antipsychotics have utility in treating acute agitation and aggression in manic episodes of bipolar disorder. Subgroup analyses from trials treating manic phase bipolar disorder, and an open-label study of rapid cycling, have suggested that atypical antipsychotics may be useful for the treatment of mixed states and rapid cycling. Several studies have suggested that atypical antipsychotics may be useful in treatment-refractory episodes of bipolar disorder. The current available data suggest greater efficacy of the atypical antipsychotics in mania than in depression, although the data are fairly clear that induction of depression is not an issue with the atypical antipsychotics. A number of trials are underway that will hopefully address many of the questions still pending.

Atypical mood stabilizers : a 'typical' role for atypical antipsychotics

Objective: To assess the potential role of atypical antipsychotics as mood stabilizers.

Method: A MedLine, PsychLIT, PubMed, and EMBASE literature search of papers published up to December 2004 was conducted using the names of atypical antipsychotics and a number of key terms relevant to bipolar disorder. Additional articles were retrieved by scrutinizing the bibliographies of review papers and literature known to the authors. Data pertinent to the objective was reviewed according to the various phases of bipolar disorder.

Results: The data is most substantive for the use of atypical antipsychotics in mania, to the extent that an argument for a class effect of significant efficacy can be made. This does not extend to bipolar depression, however, good data is now emerging for some agents and will need to be considered for each individual agent as it accumulates. As regards mixed states and rapid cycling the evidence is thus far sparse and too few maintenance studies have been conducted to make any firm assertions. However, with respect to long-term therapy the atypical antipsychotics do have clinically significant side-effects of which clinicians need to be aware.

Conclusion: Based on the evidence thus far it is perhaps premature to describe the atypical antipsychotics as mood stabilizers. Individual agents may eventually be able to claim this label, however, much further research is needed especially with respect to maintenance and relapse prevention.

Atypical antipsychotics for bipolar disorder : overblown or blown over?

Objective：Developments in the pharmacological treatment of bipolar disorder are of much interest, as the chronicity and disability of the disorder become better understood, and as treatment goals have shifted to emphasise early control of illness course and maintenance of euthymia in addition to acute episodic remission. Atypical antipsychotics have emerged as treatment options, and this paper aims to review the evidence for their role in bipolar disorder.

Methods：A MEDLINE search was conducted for publications up till October 2006.

Results：The search yielded a number of randomised, controlled clinical trials of various atypical antipsychotics as monotherapy or adjunctive therapy in bipolar disorder. The majority of such trials have investigated their efficacy in acute mania, with fewer studies devoted to acute bipolar depression or maintenance treatment. There are no specific trials on mixed states, which have mainly been studied together with bipolar mania. The most robust evidence supports a class effect of atypical agents in the treatment of mania.

Conclusions：There are placebo-controlled trials that support the efficacy of olanzapine and quetiapine in bipolar depression, and of olanzapine and aripiprazole as maintenance treatment. There is strong support for the role of atypical antipsychotics in bipolar disorder management despite a relatively narrow literature base, chiefly for the treatment of mania. However, these findings need to be replicated, and further investigation is warranted to clarify their spectrum of efficacy in bipolar disorder.

Peripheral brain-derived neurotrophic factor in schizophrenia and the role of antipsychotics: meta-analysis and implications

It has been postulated that schizophrenia (SZ) is related to a lower expression of brain-derived neurotrophic factor (BDNF). In the past few years, an increasing number of divergent clinical studies assessing BDNF in serum and plasma have been published. It is now possible to verify the relationship between BDNF levels and severity of symptoms in SZ as well as the effects of antipsychotic drugs on BDNF using meta-analysis. The aims of this study were to verify if peripheral BDNF is decreased in SZ, whether its levels are correlated with positive and negative symptomatology and if BDNF levels change after antipsychotic treatment. This report consists of two distinct meta-analyses of peripheral BDNF in SZ including a total of 41 studies and more than 7000 participants: (1) peripheral BDNF levels in serum and plasma were moderately reduced in SZ compared with controls. Notably, this decrease was accentuated with the disease duration. However, the extent of peripheral BDNF level decrease did not correlate with the severity of positive and negative symptoms. (2) In plasma, but not serum, peripheral BDNF levels are consistently increased after antipsychotic treatment irrespective of the patient's response to medication. In conclusion, there is compelling evidence that there are decreased levels of peripheral BDNF in SZ, in parallel to previously described reduced cerebral BDNF expression. It remains unclear whether these systemic changes are causally related to the development of SZ or if they are merely a pathologic epiphenomenon.Molecular Psychiatry advance online publication, 30 September 2014; doi:10.1038/mp.2014.117.

Pharmacotherapy of bipolar disorder: the role of atypical antipsychotics and experimental strategies.

Bipolar disorder, despite being a common and debilitating illness, has remarkably few pharmacological therapeutic options, the majority of which, with the exception of lithium, have been borrowed from other medical indications. Furthermore the quantity and quality of controlled clinical data are considerably smaller than in conditions of comparable severity and frequency. Not surprisingly, the clinical outcome of bipolar disorder is frequently suboptimal. Fortunately there are a growing number of novel therapeutic options for its treatment such as atypical antipsychotics, calcium channel blockers and omega-3 fatty acids. This paper summarizes some of the data regarding these "experimental" therapeutic options, focusing principally on atypical antipsychotics as these are now widely prescribed in the management of bipolar disorder.

C-reactive protein is increased in schizophrenia but is not altered by antipsychotics : meta-analysis and implications

The inflammatory hypothesis of schizophrenia (SZ) posits that inflammatory processes and neural-immune interactions are involved in its pathogenesis, and may underpin some of its neurobiological correlates. SZ is the psychiatric disorder causing the most severe burden of illness, not just owing to its psychiatric impairment, but also owing to its significant medical comorbidity. C-reactive protein (CRP) is a commonly used biomarker of systemic inflammation worldwide. There are some conflicting results regarding the behaviour of CRP in SZ. The aims of this study were to verify whether peripheral CRP levels are indeed increased in SZ, whether different classes of antipsychotics divergently modulate CRP levels and whether its levels are correlated with positive and negative symptomatology. With that in mind, we performed a meta-analysis of all cross-sectional studies of serum and plasma CRP levels in SZ compared to healthy subjects. In addition, we evaluated longitudinal studies on CRP levels before and after antipsychotic use. Our meta-analyses of CRP in SZ included a total of 26 cross-sectional or longitudinal studies comprising 85 000 participants. CRP levels were moderately increased in persons with SZ regardless of the use of antipsychotics and did not change between the first episode of psychosis and with progression of SZ (g=0.66, 95% confidence interval (95% CI) 0.43 to 0.88, P<0.001, 24 between-group comparisons, n=82 962). The extent of the increase in peripheral CRP levels paralleled the increase in severity of positive symptoms, but was unrelated to the severity of negative symptoms. CRP levels were also aligned with an increased body mass index. Conversely, higher age correlated with a smaller difference in CRP levels between persons with SZ and controls. Furthermore, CRP levels did not increase after initiation of antipsychotic medication notwithstanding whether these were typical or atypical antipsychotics (g=0.01, 95% CI -0.20 to 0.22, P=0.803, 8 within-group comparisons, n=713). In summary, our study provides further evidence of the inflammatory hypothesis of SZ. Whether there is a causal relationship between higher CRP levels and the development of SZ and aggravation of psychotic symptoms, or whether they are solely a marker of systemic low-grade inflammation in SZ, remains to be clarified.

Drug bioactivation, covalent binding to target proteins and toxicity relevance

A number of therapeutic drugs with different structures and mechanisms of action have been reported to undergo metabolic activation by Phase I or Phase II drug-metabolizing enzymes. The bioactivation gives rise to reactive metabolites/intermediates, which readily confer covalent binding to various target proteins by nucleophilic substitution and/or Schiff's base mechanism. These drugs include analgesics (e.g., acetaminophen), antibacterial agents (e.g., sulfonamides and macrolide antibiotics), anticancer drugs (e.g., irinotecan), antiepileptic drugs (e.g., carbamazepine), anti-HIV agents (e.g., ritonavir), antipsychotics (e.g., clozapine), cardiovascular drugs (e.g., procainamide and hydralazine), immunosupressants (e.g., cyclosporine A), inhalational anesthetics (e.g., halothane), nonsteroidal anti-inflammatory drugs (NSAIDSs) (e.g., diclofenac), and steroids and their receptor modulators (e.g., estrogens and tamoxifen). Some herbal and dietary constituents are also bioactivated to reactive metabolites capable of binding covalently and inactivating cytochrome P450s (CYPs). A number of important target proteins of drugs have been identified by mass spectrometric techniques and proteomic approaches. The covalent binding and formation of drug-protein adducts are generally considered to be related to drug toxicity, and selective protein covalent binding by drug metabolites may lead to selective organ toxicity. However, the mechanisms involved in the protein adduct-induced toxicity are largely undefined, although it has been suggested that drug-protein adducts may cause toxicity either through impairing physiological functions of the modified proteins or through immune-mediated mechanisms. In addition, mechanism-based inhibition of CYPs may result in toxic drug-drug interactions. The clinical consequences of drug bioactivation and covalent binding to proteins are unpredictable, depending on many factors that are associated with the administered drugs and patients. Further studies using proteomic and genomic approaches with high throughput capacity are needed to identify the protein targetsof reactive drug metabolites, and to elucidate the structure-activity relationships of drug's covalent binding to proteins and their clinical outcomes.

Common structural basis for central nervous system drug design

The main theme of this thesis is that there is a common structural basis for drugs acting on the central nervous system (CNS), and that this concept may be used to design new CNS-active drugs which have greater specificity and hence less side-effects. To develop these ideas, the biological basis of how drugs modify CMS neurotransmission is described, and illustrated using dopaminergic pathways. An account is then given of the use of physicochemical concepts in contemporary drug design. The complete conformational analysis of several antipsychotic drugs is used to illustrate some of these techniques in the development of a model for antipsychotic drug action. After reviewing current structure-activity studies in several classes of CNS drugs (antipsychotics, anti-depressants, stimulants, hal1ucinogens, anticonvulsants and analgesics), a hypothesis for a common structural basis of CNS drug action is proposed- This is based on a topographical comparison of the X-ray structures of eight representative CNS-active drugs, and consists of three parts: 1.there is a common structural basis for the activity of many different CNS-active drug classes; 2. an aromatic ring and a nitrogen atom are the primary binding groups whose topographical arrangement is fundamental to the activity of these drug classes; 3. the nature and placement of secondary binding determines different classes of CNS drug activity. A four-Point model for this common structural basis is then defined using 14- CNS-active drug structures that include the original eight used in proposing the hypothesis. The coordinates of this model are: R1 (0. 3.5, 0), R2 (0, -3.5, O), N (4.8. -0.3, 1.4), and R3 (6.3, 1.3, 0), where R1 and R2 represent the point locations of a hydrophobic interaction of the common aromatic ring with a receptor, and R3 locates the receptor point for a hydrogen bond involving the common nitrogen, N. Extended structures were used to define the receptor points R1, R2 and R3, and the complete conformational space of each of the 14 molecules was considered. It is then shoun that the model may be used to predict whether a given structure is likely to show CNS activity: a search over 1,000 entries in the current Merck Index shows a high probability (82%) of CNS activity in compounds fitting the structural model. Analysis of CNS neurotransmitters and neuropeptides shows that these fit the common model well. Based on the available evidence supporting chemical evolution, protein evolution, and the evolution of neurotransmitter functions, it is surmised that the aromatic ring/nitrogen atom pharmacophore proposed in the common model supports the idea of the evolution of CNS receptors and their neurotransmitters, possibly from an aromatic amine or acety1cho1ine acting as a primaeval communicating molecule. The third point in the hypothesis trilogy is then addressed. The extensive conformation-activity analyses that have resulted in well-defined models for five separate CNS drug classes are used to map out the locations of secondary binding groups relative to the common model for anti-psychotics, antidepressants, analgesics, anticholinergics, and anticonvulsants. With this information, and knowledge derived from receptor-binding data, it is postulated that drugs having specified activity could be designed. In order to generate novel structures having a high probability of CNS-activity, a process of drug design is described in which known CNS structures are superimposed topographically using the common model as a template. Atoms regarded as superfluous may be selectively deleted and the required secondary binding groups added in predicted locations to give novel structures. It is concluded that this process provides the basis for the rational design of new lead compounds which could further be optimized for potent and specific CNS activity.