摘要:

Catechol-O-methyltransferase (COMT) inhibitors are used in patients with Parkinson's disease to reduce the complications associated with long term levodopa therapy. By inhibiting catecholamine catabolism, they extend the pharmacological effects of levodopa and improve patient disability.Also as a result of the inhibition of catecholamine catabolism, COMT inhibitors may have some positive effects on cognitive functions and on some psychiatric symptoms, such as depression, that can occur in individuals with Parkinson's disease.Animal studies have shown that COMT inhibitors may exert a positive effect on some cognitive functions, such as short term and working memory, and learning. However, results of these studies are, in some cases, difficult to interpret. One clinical study of patients with Parkinson's disease who were treated with the COMT inhibitor tolcapone as an adjuvant to long term levodopa therapy showed a positive effect on several cognitive aspects. These results warrant a wider investigation of the cognitive effects of COMT inhibitors in patients with Parkinson's disease.

ISSN:1172-7047    

出版商:ADIS    

年代:2000

数据来源: ADIS

摘要:

Peritumoural brain oedema can aggravate the mass effect of tumours and lead to additional complications. The oedema associated with brain tumours is vasogenic in nature and is due to an increase in the permeability of the blood-brain barrier. The cause of this increased permeability it not entirely clear but is likely to be associated with the production of various substances by tumours (such as oxygen free radicals), an inflammatory response and/or an effect on the central vasopressin system.The diagnosis of peritumoural brain oedema is assisted by the use of imaging techniques such as computed tomography, and magnetic resonance imaging and spectroscopy.The treatment of peritumoural oedema involves the use of glucocorticoids or osmotic dehydrating agents, such as mannitol and glycerol, and the avoidance of factors that increase intracranial pressure. Based on current knowledge of the causes of peritumoural oedema, future strategies may include the use of agents with antioxidant properties [such as lazaroids (tirilazad)], corticotropin-releasing factor and vasopressin inhibitors.

ISSN:1172-7047    

出版商:ADIS    

年代:2000

数据来源: ADIS

摘要:

The evaluation and treatment of depression is an important component of the management of individuals with Parkinson's disease. This review summarises current knowledge on the epidemiology, pathophysiology and treatment of depression in Parkinson's disease.Limited information is available regarding the pathophysiology of depression in Parkinson's disease and the effectiveness of treatment. Selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) are commonly used but more information is needed regarding their tolerability and antidepressant efficacy in patients with Parkinson's disease, and their effect on motor function. Antidepressants can interact with selegiline (deprenyl) to cause the ‘serotonin syndrome’, although retrospective chart reviews indicate that this is rare. While several case reports have noted worsening parkinsonian motor features with SSRI use, open-label prospective studies have not substantiated these findings. Further double-blind, prospective studies would be valuable to further evaluate the tolerability and efficacy of antidepressants in Parkinson's disease.

ISSN:1172-7047    

出版商:ADIS    

年代:2000

数据来源: ADIS

摘要:

Nicotine replacement therapy (NRT) has been the mainstay of smoking cessation therapy for >15 years. However, 70 to 90% of smokers fail to quit despite NRT. Non-nicotine medications have been investigated as alternative therapies to achieve smoking cessation.NRT is believed to work by relieving withdrawal symptoms, and perhaps by desensitising nicotinic cholinergic receptors. Non-nicotine medications may work in a variety of ways, including nicotinic cholinergic receptor agonism (lobeline), nicotine-like effects on neurotransmitter systems (antidepressants, clonidine), nicotinic cholinergic receptor antagonism (mecamylamine) and sensory stimulation/aversion (citric or ascorbic acid inhalants or spray, silver acetate).The only non-nicotine drug approved for smoking cessation in the US is the antidepressant amfebutamone (bupropion). Two large clinical trials have demonstrated the benefit of the drug, with cessation ratios more than twice that of placebo. Amfebutamone is effective in increasing smoking cessation regardless of a history of or current depression, and is generally well tolerated, although it occasionally produces agitation and in excessive doses can cause seizures.Clinical trials suggest the benefit of a number of other non-nicotine medications: the tricyclic antidepressant nortriptyline, the antihypertensive clonidine, and silver acetate. A mecamylamine-nicotine combination may be effective, and sensory stimulants, such as citric or ascorbic acid inhalers or sprays, might enhance the effects of nicotine or other pharmacotherapies.The availability of non-nicotine medications expands the options for smoking cessation therapy. A stepped care approach for the selection of pharmacotherapies is presented in this review. With this approach, initial therapy would involve an attempt to quit using over-the-counter nicotine products. If this fails, therapy with other forms of NRT, such as nicotine nasal spray, or non-nicotine medication such as amfebutamone or other antidepressants, and/or intensive behavioural therapy, should be tried. Failure to quit at the second step should lead to combinations of nicotine and non-nicotine therapies, as well as clonidine and other newer treatments.Future prospects for the pharmacotherapy of smoking cessation include the use of nicotine receptor subtype−specific agonists and antagonists, targeted to deal with specific reinforcement and/or specific withdrawal symptoms. Also of future interest is the development of nicotine antibodies that might neutralise the effects of nicotine. It is hoped that ultimately medications can be matched with the individual characteristics of a smoker, and that smoking cessation could be facilitated in most smokers.

ISSN:1172-7047    

出版商:ADIS    

年代:2000

数据来源: ADIS

摘要:

The recent inclusion of research diagnostic criteria for premenstrual dysphoric disorder (PMDD) in the DSM-IV recognises the fact that some women in their reproductive years have extremely distressing emotional and behavioural symptoms premenstrually. Through the use of these criteria, PMDD can be differentiated from premenstrual syndrome (PMS) which has milder physical symptoms, i.e. breast tenderness, bloating, headache and minor mood changes. PMDD can also be differentiated from premenstrual exacerbation of a current psychiatric disorder or medical condition, although some women may meet criteria for a dual diagnosis.Epidemiological surveys have estimated that as many as 75% of women with regular menstrual cycles experience some symptoms of PMS. PMDD, on the other hand, is much less common. It affects only 3 to 8% of women in this group, but it is more severe and exerts a much greater psychological toll. These women report premenstrual symptoms that seriously interfere with their lifestyle and relationships. The aetiology of PMDD is largely unknown but the current consensus seems to be that normal ovarian function (rather than hormone imbalance) is the cyclical trigger for PMDD-related biochemical events within the CNS and other target organs.The serotonergic system is in close reciprocal relationship with the gonadal hormones and has been identified as the most plausible target for interventions. Thus, beyond the conservative treatment options such as lifestyle and stress management, and the more extreme interventions that eliminate ovulation altogether, the selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) are emerging as the most effective treatment options for this population.Results from several randomised placebo-controlled trials in women with PMDD, with predominantly psychological symptoms of irritability, tension, dysphoria and lability of mood, have clearly demonstrated that the SSRIs have excellent efficacy and minimal adverse effects. More recently, several preliminary studies indicate that intermittent (premenstrually only) treatment with SSRIs is equally effective in these women and, thus, may offer an attractive treatment option for a disorder that is itself intermittent.

ISSN:1172-7047    

出版商:ADIS    

年代:2000

数据来源: ADIS