摘要:

The principal constituent of cannabis, Δ9-tetrahydrocannabinol (THC), is moderately effective in treating nausea and vomiting, appetite loss, and acute and chronic pain. Oral THC (dronabinol) and the synthetic cannabinoid, nabilone, have been registered for medical use in the US and UK, but they have not been widely used because patients find it difficult to titrate doses of these drugs. Advocates for the medical use of cannabis argue that patients should be allowed to smoke cannabis to relieve these above-mentioned symptoms.Some US state governments have legislated to allow the medical prescription of cannabis, but the US federal government has tried to prevent patients from obtaining cannabis and threatened physicians who prescribe it with criminal prosecution or loss of their licence to practise. In the UK and Australia, committees of inquiry have recommended medical prescription (UK) and exemption from criminal prosecution (New South Wales, Australia), but governments have not accepted these recommendations. The Canadian government allows an exemption from criminal prosecution to patients with specified medical conditions. It has recently legislated to provide cannabis on medical prescription to registered patients, but this scheme so far has not been implemented.Some advocates argue that legalising cannabis is the only way to ensure that patients can use it for medical purposes. However, this would be contrary to international drug control treaties and is electorally unpopular. The best prospects for the medical use of cannabinoids lie in finding ways to deliver THC that do not involve smoking and in developing synthetic cannabinoids that produce therapeutic effects with a minimum of psychoactive effects. While awaiting these developments, patients with specified medical conditions could be given exemptions from criminal prosecution to grow cannabis for their own use, at their own risk.

ISSN:1172-7047    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Biomedical researchers interested in amyotrophic lateral sclerosis (ALS) must invoke newly developing technologies if we are to discover pharmaceutical treatments that will help a significant population of patients with the disease. The focus of ALS research over the last 10 years has been on reactive oxygen species (ROS) and glutamate excitotoxicity, resulting in several clinical trials and the launch of the only drug currently available for the treatment of ALS, riluzole. Unfortunately, the therapeutic benefits have been minimal, at best, and the prognosis for patients with ALS has not improved beyond very modest retardation of the disease course. By emphasising ROS and glutamate excitotoxicity, current ALS research has only partially been able to attenuate the rate of motor decline and neuronal loss associated with this illness.Clues to additional therapeutic potentialities will come from an increased understanding of the mode of cell death (apoptotic or other) and the pathways leading to neuronal demise. If death is apoptotic, inhibiting caspases may be useful. The regulatory modifications for cell death at the molecular level remain to be determined and exploited to prevent neuronal loss, although novel pathways have been recently elucidated that impact on protein aggregation and processing. Oxidative stress, seen in both familial and sporadic forms of ALS, may be only one post-translational mechanism likely to affect specific proteins essential for the health and stability of motor neurons. Protein cross-linking by transglutaminase paralleling that may lead to defects in proteasome function may also be a significant mechanism. The latest capabilities to screen protein changes in specific cells represent the kinds of advances needed to combat ALS in the third millennium.

ISSN:1172-7047    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Good-quality sleep is an important and frequently overlooked component of general health, but it is particularly essential to patients with epilepsy. Their sleep can be affected by seizures, concurrent sleep disorders and seizure treatment. Worsening sleep can result not only in poor daytime functioning but also potentially in worsening epilepsy. The effects of antiepileptic drugs (AEDs) on sleep are of particular concern. Some agents have detrimental effects on sleep, particularly benzodiazepines and barbiturates but also phenytoin and, possibly, carbamazepine. Others, especially gabapentin, seem to actually improve sleep quality. Much research in this area is confounded by the effects of seizures and concurrent conditions on sleep, making it difficult to isolate the direct effects of AEDs on sleep. But because AEDs have independent effects on sleep quality, the choice of an appropriate agent not only determines whether seizures are completely controlled but also whether the patient performs optimally on a daily basis.

ISSN:1172-7047    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

In spite of the extensive studies performed on postmortem substantia nigra from Parkinson’s disease patients, the aetiology of the disease has not yet been established. Nevertheless, these studies have demonstrated that, at the time of death, a cascade of events had been initiated that may contribute to the demise of the melanin-containing nigro-striatal dopamine neurons. These events include increased levels of iron and monoamine oxidase (MAO)-B activity, oxidative stress, inflammatory processes, glutamatergic excitotoxicity, nitric oxide synthesis, abnormal protein folding and aggregation, reduced expression of trophic factors, depletion of endogenous antioxidants such as reduced glutathione, and altered calcium homeostasis. To a large extent, the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA) animal models of Parkinson’s disease confirm these findings. Furthermore, neuroprotection can be afforded in these models with iron chelators, radical scavenger antioxidants, MAO-B inhibitors, glutamate antagonists, nitric oxide synthase inhibitors, calcium channel antagonists and trophic factors.Despite the success obtained with animal models, clinical neuroprotection is much more difficult to accomplish. Although the negative studies obtained with the MAO-B inhibitor selegiline (deprenyl) and the antioxidant tocopherol (vitamin E) may have resulted from an inappropriate choice of drug (selegiline) or an inadequate dose (tocopherol), the niggling problem that still remains is why these drugs, and others, do work in animals while they fail in the clinic. One reason for this may be related to the fact that in normal human brains the number of dopaminergic neurons falls by around 3–5% every decade, while in Parkinson’s disease this decline is greater. Brain autopsy studies have shown that by the time the disease is identified, some 70–75% of the dopamine-containing neurons have been lost. More sensitive reliable methods and clinical correlative markers are required to discern between confoundable symptomatic effects versus a possible neuroprotective action of drugs, namely, the ability to delay or forestall disease progression by protecting or rescuing the remaining dopamine neurons or even restoring those that have been lost.A number of other possibilities for the clinical failure of potential neuroprotectants also exist. First, the animal models of Parkinson’s disease may not be totally reflective of the disease and, therefore, the chemical pathologies established in the animal models may not cause, or contribute to, the progression of the disease clinically. Second, because of the series of events occurring in neurodegeneration and our ignorance about which of these factors constitutes the primary event in the pathogenic process, a single drug may not be adequate to induce neuroprotection and, as a consequence, use of a cocktail of drugs may be more appropriate. The latter concept receives support from recent complementary DNA (cDNA) microarray gene expression studies, which show the existence of a gene cascade of events occurring in the nigrostriatal pathway of MPTP, 6-OHDA and methamphetamine animal models of Parkinson’s disease.Even with the advent of powerful new tools such as genomics, proteomics, brain imaging, gene replacement therapy and knockout animal models, the desired end result of neuroprotection is still beyond our current capability.

ISSN:1172-7047    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

The management of neurological and psychiatric disorders is a vast and evolving area for researchers, primary care physicians and specialists. To help you keep up to date with the latest advances worldwide on all aspects of drug therapy for neurological and psychiatric disorders, this section of the journal brings you information selected from the drug therapy reporting serviceInpharma Weekly1. The following reports are selected from the latest issues, summarising the most important research and development news, clinical studies, treatment guidelines, pharmacological, pharmacoeconomic and adverse drug reactions/interactions news, and expert opinion pieces published across a broad range of literature sources.

ISSN:1172-7047    

出版商:ADIS    

年代:2003

数据来源: ADIS