摘要:

A better  understanding of the human  immune  system  and its complex interactions has resulted in new insights into the pathoaetiological mechanisms of psychiatric disorders. As a result, new treatment options are being explored. Several findings suggest that an imbalanced immune response is involved in the pathophysiology of schizophrenia. COX-2 inhibitors are known to influence the immune system in a way that may redirect this imbalance. Based on these suggestions, the COX-2 inhibitor celecoxib has been tested as a possible adjunctive therapeutic approach in the treatment of schizophrenia. While the first trial using celecoxib as add-on therapy to an atypical antipsychotic showed a significant beneficial effect, recent studies demonstrated that this effect may be limited to patients with recent-onset schizophrenia.

ISSN:1172-7047    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

Stroke is a very complex disease influenced by many risk factors: genetic, environmental and comorbidities, such as hypertension, diabetes mellitus, obesity and having had a previous stroke. Neuroprotective therapies that have been found to be successful in laboratory animals have failed to produce the same benefits in clinical trials. Currently, a re-analysis of the clinical trial failures is underway and new therapeutic approaches using the growing knowledge from neurogenesis and neuroinflammation studies, combined with the information from gene expression studies, are taking place. This review focusses on possible ways to identify therapeutic targets using the new discoveries in neuroinflammation and intrinsic regenerative mechanisms of the brain.Molecular events associated with ischaemia trigger an environment for inflammation. Within the ischaemic region and its penumbra, a battery of chemokines and cytokines are released, which have both detrimental and beneficial effects, depending on the specific timepoint after injury and the current activation status of microglia/macrophages. Preventive therapies and treatments for stroke may be established by identifying the genes that are responsible for the induction of those phenotypic changes of microglia/macrophages that switch them to become players in tissue repair and regeneration processes.To aid in the establishment of new target sources for novel therapeutic agents, animal stroke models should closely mimic stroke in humans. To do so, these models should take into account the various risk factors for stroke. For example, hypertensive animals have a more vulnerable blood-brain barrier that in turn may trigger a greater degree of damage after stroke. Furthermore, in aged animals an accelerated astrocytic and microglial reaction has been observed and the regenerative capacity of aged brains is not as high as young brains. Improvements in animal models may also help to ensure better success rates of potential therapies in clinical studies.Inflammation in the brain is a double-edged sword – characterised by the deleterious effect of nerve cell damage and nerve cell death, as well as the beneficial influence on regeneration. The major challenge to develop successful stroke therapies is to broaden the knowledge regarding the underlying pathologic processes and the intrinsic mechanisms of the brain to drive regenerative and plasticity-related changes. On this basis, new concepts can be created leading to better stroke therapy.

ISSN:1172-7047    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

The disease-modifying agents currently used in the treatment of multiple sclerosis (MS) are not completely effective and are associated with adverse effects and high costs. Thus, alternative treatment options are highly desirable. HMG-CoA reductase inhibitors (statins), widely prescribed as cholesterol-lowering agents, may be a future treatment option for MS – either in an add-on therapy regimen or alone – as they have been shown to exhibit potent immunomodulatory effects. Several recent reports have demonstrated that HMG-CoA reductase inhibitors prevent and reverse chronic and relapsing experimental autoimmune encephalomyelitis, an animal model of MS. Furthermore,in vitroexperiments with human immune cells have shown an immunomodulatory mode of action of HMG-CoA reductase inhibitors that is comparable to that of interferon-β, an established treatment for MS. An open-label clinical trial assessing simvastatin treatment in patients with MS revealed a significant decrease in the number and volume of new lesions, as assessed using magnetic resonance imaging, and a favourable safety profile. A large multicentre, placebo-controlled phase II clinical trial assessing atorvastatin in patients with a clinically isolated syndrome (i.e. a single clinical event that is indicative of demyelination, and that predisposes to the development MS) has recently been initiated. However, prospective placebo-controlled trials of HMG-CoA reductase inhibitors in definite MS are difficult to perform because of ethical and financial issues. Furthermore, overly optimistic reports in the popular media, as well as the often uncontrolled access to HMG-CoA reductase inhibitors by patients with MS, complicate the evaluation of HMG-CoA reductase inhibitors as a realistic future treatment option for MS.

ISSN:1172-7047    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

The introduction of antipsychotics in the 1950s revolutionised the treatment of schizophrenia, but it soon became apparent that a substantial number of patients demonstrated a suboptimal response to these antipsychotics. Clozapine proved to be beneficial in patients whose symptoms were treatment resistant, but it too had limitations, with as many as 40–70% of those treated with clozapine demonstrating inadequate response to this drug as well. The availability of other ‘atypical’ antipsychotics offers options, but clozapine appears to remain the most effective option in treatment-resistant schizophrenia. This, of course, raises the question of what to do when clozapine is only partially effective.To address the issue of treatment in patients who have demonstrated a suboptimal response to clozapine, efforts have focused on a variety of augmentation strategies, including numerous medications and electroconvulsive therapy. The current body of evidence consists largely of data from smaller open trials and case series/reports, although data from a limited number of controlled studies are now available. Not surprisingly, the evidence drawn from the former is more supportive of augmentation strategies, although the controlled trials are not without positive findings.The available information is certainly not so overwhelming as to endorse any single augmentation approach. Indeed, it argues for more controlled data and cautions us regarding the cost-benefit ratio in adopting this strategy. Over and above the added adverse effects of another treatment, there is evidence to indicate that actual clinical worsening can occur.Without compelling evidence, clinicians must resort to guiding principles. The potential benefits of augmentation cannot be ruled out, but it should be approached with caution and in a systematic fashion. Factors compromising clozapine response should first be ruled out, and any augmentation trials should be guided by existing evidence and a treatment plan that incorporates a clear understanding of target symptoms. A means of evaluating outcome effectively needs to be in place, and the trial should be circumscribed to prevent needless polypharmacy.A priori, an endpoint needs to be established and the trial discontinued unless results firmly support added benefits.

ISSN:1172-7047    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

Neuroscientific developments have promulgated interest in developing efficacious medications for the treatment of substance dependence. Previous pharmacological strategies that involve the use of relatively specific medications to alter corticomesolimbic dopaminergic neuronal activity – the critical pathway for expression of the reinforcing effects of abused drugs – have yielded modest efficacy in the treatment of alcohol dependence, and no medication has been established as a treatment for cocaine dependence. Since corticomesolimbic dopaminergic neurons interact with other neurotransmitters that modulate the effects of dopamine in the nucleus accumbens, would it not be possible to control these dopaminergic effects more reliably with a medication that acts contemporaneously on more than one neuromodulator of dopaminergic function? Further, since the long-term use of either alcohol or cocaine results in neuronal adaptations as a result of sensitisation, would the chances of effective therapy not be bolstered by administering a medication that was also able to mitigate these chronic effects? Thus, a new conceptual approach is needed.My proposal is that a medication – in this case topiramate – that principally potentiates inhibitory GABAAreceptor-mediated input and antagonises excitatory glutamatergic afferents to the corticomesolimbic dopaminergic system should have therapeutic potential in treating either alcohol or cocaine dependence or perhaps both. This is because the principal neurochemical effects of topiramate would not only serve to decrease the acute reinforcing effects of alcohol or cocaine, but might also facilitate cessation of their use following a period of long-term use by decreasing neuronal sensitisation.This overview highlights the scientific concepts and clinical evidence for the development of topiramate in the treatment of alcohol dependence and introduces preliminary evidence to indicate that it might also have utility in treating cocaine dependence. Finally, to place the material on topiramate in context, information has been included on the utility and development of other medications that modulate GABA- or glutamate-mediated neuronal systems for the treatment of alcohol or cocaine dependence.

ISSN:1172-7047    

出版商:ADIS    

年代:2005

数据来源: ADIS