Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The initial treatment of Parkinson's disease should be addressed to improve symptoms, slow down the progression of the illness and avoid long and short term complications. Drugs currently available for symptomatic treatment are levodopa, dopaminergic agonists, anticholinergics and amantadine. Levodopa is still the goldstandard. Both the standard preparations of carbidopa/levodopa or benserazide/levodopa and the slow release preparations are suitable for initial treatment. However, when to start levodopa remains controversial. Dopaminergic agonists are useful symptomatic drugs. They can be used in monotherapy, but usually require the addition of levodopa to obtain a satisfactory long term therapeutic response. Used as adjuvant treatment to levodopa, they help lowering the dosage of levodopa. Anticholinergic drugs effectively improve symptoms such as tremor and rigidity but their use is limited by their side effects, particularly in older people. Amantadine may be a useful drug for initial treatment of Parkinson's disease when symptoms are not severe. Symptomatic treatment should be considered individually in each patient. If there is only slight disability, treatment may be started with amantadine alone or with a dopaminergic agonist. If there is greater disability, levodopa or the simultaneous use of levodopa and a dopaminergic agonist should be considered. Anticholinergic drugs should be reserved for young patients with tremor as the main symptom. The newer dopamine agonists and inhibitors of catachol-o-methyltransferase (COMT) are coming therapeutic options. Selegiline, a MAOB inhibitor with a possible neuroprotective effect, should also be considered as initial option for Parkinson's disease.
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PMID:[Initial treatment of Parkinson's disease]. 928 Jun 84

Pregnancy is rare in Parkinson's disease (PD). In the literature on studies of antiparkinsonian drugs in animals during pregnancy, there are reports on malformations of the skeletal and circulatory system. However, the majority of studies in animals have not shown any teratogenicity. Amantadine has been teratogenic in rats and selegiline has caused neurochemical and behavioral alterations in rats when coadministered with clorgyline. The published experience with humans consists of 35 pregnancies among 26 women suffering from PD, including this report, and a number of cases treated with antiparkinsonian agents for other reasons. With the exception of the majority of the cases where amantadine was used, complications have been rare. However, there are indications that suggest a possible risk of a woman's parkinsonism worsening in connection with pregnancy. We also report the case of a woman with PD who was treated with L-dopa-benserazide during an uncomplicated pregnancy and gave birth to a healthy boy without experiencing any worsening of her PD.
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PMID:Pregnancy in Parkinson's disease: a review of the literature and a case report. 991 78

Amantadine, originally used in the treatment and prophylaxis of influenza infection, has also proved beneficial in drug-induced Parkinsonism, Parkinson's disease, traumatic head injury, dementia, multiple sclerosis and cocaine withdrawal. Amantadine appears to act through several pharmacological mechanisms, none of which has been identified as the one chief mode of action. It is a dopaminergic, noradrenergic and serotonergic substance, blocks monoaminoxidase A and NMDA receptors, and seems to raise beta-endorphin/beta-lipotropin levels. However, it is still uncertain which of these actions are relevant in therapeutic doses. One new aspect is the antiviral effect of amantadine on Borna disease virus, which it is suspected may possibly play a role in affective disorders. All of these actions could constitute an antidepressant property, and it is suggested that amantadine might work as an antidepressant not through one, but through several mechanisms thought to be related to antidepressant activity. Effects of amantadine on symptoms of affective disorders have been demonstrated in several trials administering it for varying purposes. Additionally, animal studies as well as clinical trials in humans have hinted at an antidepressant activity of amantadine. We present here an overview of the current data. However, only a limited body of evidence is available, and further studies are needed to investigate the efficacy of amantadine as well as its modes of action in depression.
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PMID:Possible use of amantadine in depression. 1033 62

The antiviral agent amantadine specifically inhibit influenza A virus infection, but the emergence of drug-resistant viruses occur more readily with amantadine treatment. In human influenza viruses, single amino acid changes at 4 sites spanning the transmembrane domain of the M2 protein can confer drug resistance. Amantadine was approved for treatment of Parkinson's disease in 1975, and for the influenza A virus infection in November 1998, in Japan. Annual consumption of amantadine for influenza treatment increased suddenly after the approval. According to our previous report, the predominant genotype of resistant virus is the substitution S-31-N in M2 both in vitro and in clinical samples, as in the other reports. Based on the above findings, we focused on single amino acid change at position 31 (genotype S-31-N) and applied polymerase chain-reaction restriction fragment length polymorphism (PCR-RFLP), directly from throat swab samples, by using primers that insert a restriction site for Sca I. With this technique, we surveyed the incidence of amantadine resistant viruses in nursing homes, Niigata, Japan. Thirty-one (22.0%) of 141 PCR positive samples from 8 nursing homes in 1998-99 season showed resistant patterns, and only 6 (19.4%) of them were after the administration of amantadine for treatment. All of these 8 nursing homes used amantadine for Parkinson's disease, but only half of them used the drug for influenza A infection. The incidence of resistant viruses was not significantly different from facilities with amantadine for influenza treatment to those without, 25.5% and 14.0% respectively. The occurrence of outbreaks and sporadic illness in those facilities, with different administration status were observed, but fortunately we could not find any evidence to relate the emergence of resistant viruses to the outbreaks. This is the first report that the resistant influenza viruses already exist in nursing facilities where amantadine was used for not only influenza but also Parkinson's disease in Japan.
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PMID:[Incidence of amantadine-resistant influenza A (genotype Ser-31-Asn) in nursing homes in Niigata, Japan]. 1101 12

Early and correct diagnosis and treatment of Parkinson's disease (PD) are crucial for the patient's well being. At the first visit, it is important to deal with the patient's misconceptions of the disease and its course, to offer sources of information and to suggest exercises. To make a correct initial diagnosis of PD we need to assess the course of the initial levodopa responsiveness. The most frequent challenges in diagnosing PD are the conditions of essential tremor and multiple system atrophy. PD has 3 stages of development: (i) early--from the onset of symptoms to the appearance of motor fluctuations; (ii) middle--from motor fluctuations to the appearance of moderate-to-severe disability; and (iii) advanced--when moderate-to-severe disability is present. The medical treatment of early PD should be started when functional disability appears, which is a different threshold for each patient. For patients below 65 years old, or above 65 years old but with preserved mental function and with no severe comorbidity, initial monotherapy with a dopamine agonist is advisable. This approach appears to delay the appearance and reduce the amount of late motor complications with subsequent levodopa treatment. All dopamine agonists have similar efficacy, which is less than that of levodopa. It is important to consider the adverse effect profile when a choice for initial or adjunctive therapy is made. When levodopa therapy is started as an adjunct in younger patients or as initial monotherapy in older patients, sustained-release levodopa preparations are preferred. They have a longer half-life and possibly stimulate the dopamine receptors more continuously. Anticholinergic drugs are appropriate for younger patients with tremor-dominant PD. Amantadine is mainly used for dyskinesia control. Catechol-O-methyl-transferase inhibitors and neurosurgery are not treatments of choice for early PD but can be very effective for more advanced disease. The presence of presymptomatic markers of PD, such as changes in odour detection, handwriting, speech, movement time of self-initiated motor acts, personality traits, presence of antibodies against dopaminergic neurons, pattern of positron emission tomography results, appearance of mitochondrial DNA mutation profiles, etc., appear to be very important in the light of the emerging neuroprotective therapies. Neuroprotection is aimed at slowing the rate of disease progression. Selegiline has been shown to cause a mild delay in the need for levodopa, possibly suggesting some protection. However, this initial benefit was not sustained in long term studies. Currently, there is no neuroprotective drug for PD.
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PMID:Early Parkinson's disease: what is the best approach to treatment. 1104 17

Amantadine has been proved to be beneficial in Parkinson's disease. Although it is still uncertain which neurochemical events are modified at therapeutic doses, an increase in dopaminergic tone secondary to NMDA receptor blockade and a direct inhibition of the glutamatergic overactivity have been suggested to be involved in its clinical effects. The aim of this study was to evaluate the effects of amantadine on the dopaminergic system by measuring the in vivo binding of [11-C]raclopride to D2 dopamine receptors in the basal ganglia of 6 patients with idiopathic Parkinson's disease. Each patient underwent a PET study, before and after 14 days of treatment with amantadine (200 mg/day). Repeated treatment with therapeutic doses of amantadine induced a moderate increase in the in vivo binding of [11C]raclopride in the putamen of PD patients. This observation indicates that in PD patients, 200 mg/day amantadine does not produce an increase in extracellular levels of dopamine sufficiently to inhibit raclopride binding or that, if present, is it masked by a concurrent increase in receptor availability, as recently reported in rat striatum.
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PMID:A PET study with [11-C]raclopride in Parkinson's disease: preliminary results on the effect of amantadine on the dopaminergic system. 1148 82

It has been reported that non-Caucasian populations often suffer from an atypical type of Parkinson's disease (PD) characterized by poor levodopa response, early cognitive impairment and autonomic dysfunction. We tested the effect of a well known antiparkinsonian compound, amantadine, in 23 Afro-American patients with PD in a time-limited (six months), open-label, clinical and electrophysiological (simultaneously recorded primary and cognitive visual evoked potentials) trial. Patients were given amantadine either as monotherapy (first group) or added to levodopa treatment (second group). Amantadine produced a significant (p < 0.05) shortening of the latency of the event related potential (P300) obtained in a visual discrimination paradigm, while the timing of primary visual evoked potentials was little or not at all affected. Amantadine also showed significant beneficial effects (p < 0.01) on the motor score of both groups as assessed by the Rated Parkinson's Disease Neurological Exam, including items related to autonomic dysfunction. These findings suggest that amantadine alone and as adjuvant to levodopa can significantly improve both the speed of visual cognitive processing and the clinical score in non caucasian patients with PD. For these populations amantadine can be thus considered a helpful therapeutical option.
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PMID:The visuo-cognitive and motor effect of amantadine in non-Caucasian patients with Parkinson's disease. A clinical and electrophysiological study. 1179 61

Reserpine-induced catatonia is a widely accepted animal model of Parkinson's disease. In the present study, reserpine (5 mg/kg i.p.) and alpha-methylpara-tyrosine (AMPT) (200 mg/kg i.p.) induced catatonia in mice 20 h and 1 h before the experiment, respectively, as assessed using the rota-rod and bar tests after reserpine treatment. There was a significant decrease in fall-off time in the rota-rod test and a significant increase in time spent on the bar in the bar test as compared to the untreated control mice. Combination therapy with L-DOPA (100 mg/kg i.p.) and carbidopa (10 mg/kg i.p.) was less effective in reversing catatonia as compared to higher doses of L-DOPA (200 mg/kg i.p.) and carbidopa (20 mg/kg i.p.), which showed intense hyperactivity in reserpinized mice. Pretreatment with nitecapone (30 mg/kg i.p.), a COMT inhibitor, or selegiline (10 mg/kg i.p.), a MAO-B inhibitor potentiated the motor stimulant actions of subthreshold doses of the L-DOPA (100 mg/kg i.p.) and carbidopa (10 mg/kg i.p.) combination. Amantadine (40 mg/kg i.p.), but not bromocriptine, potentiated the effects of L-DOPA treatment. The NMDA antagonistic action of amantadine may have beneficial effects. It is concluded that COMT and MAO-B enzymes play an important role in the metabolism of dopamine and administration of a COMT or MAO-B inhibitor may prove to be a better adjunct to L-DOPA therapy than a dopamine receptor agonist in Parkinson's disease.
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PMID:Nitecapone and selegiline as effective adjuncts to L-DOPA in reserpine-induced catatonia in mice. 1198 Mar 84

Amantadine, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist known to increase dopamine synthesis and release in the striatum, is frequently associated with L-DOPA in the treatment of Parkinson's disease. However, the biochemical mechanisms involved in the effect of amantadine and the consequences of its repetitive administration on the modulation of striatal dopamine transmission still need to be clarified. We have investigated the effects of short-term amantadine treatments on the expression of dopamine receptors and the functional coupling to G proteins in rat striatal membranes. Dopamine-induced stimulation of guanosine 5'-[gamma-35S]triphosphate ([35S]GTPgammaS) binding was significantly enhanced (40%) in striatum homogenates from rats treated for 4 days with amantadine (40 mg/kg, i.p.) compared to vehicle-treated animals. This effect was specific for dopamine receptors and was transient as no significant modifications were observed when animals were treated for either 2 or 7 days. Administration of amantadine did not directly affect the animal behaviour. However, treated animals exhibited hypersensitive dopamine transmission since rats treated for 4 days showed exacerbated responses to a single apomorphine administration (enhanced locomotor activity and reduced stereotypy). Since the effects of amantadine administration differ from those usually observed with direct dopamine receptor agonists or other NMDA receptor antagonists, we suggest that multiple biochemical mechanisms contribute to the modulation of dopamine transmission by amantadine.
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PMID:Hypersensitivity of dopamine transmission in the rat striatum after treatment with the NMDA receptor antagonist amantadine. 1221 97

Amantadine, is a non competitive NMDA receptors antagonist that has been proved beneficial in Parkinson's disease. However its mechanism of action at therapeutic doses is still under discussion. Aim of this study was to evaluate the effect of repeated administration of amantadine on striatal dopaminergic system by measuring [(11)C]raclopride binding to striatal D(2) dopamine receptors, in patients with moderate idiopathic Parkinson's disease. Eight patients completed the study undergoing a PET scan, before and after 10-14 days treatment with Amantadine (200 mg/day). Patients were on treatment with L-DOPA, which was suspended 1 night before each PET scans, and free from dopaminergic agonists, anticholinergic and antidepressants. Amantadine treatment significantly increased [(11)C-]Raclopride binding (caudate: 10% p = 0.04; putamen 11% p = 0.01). A slight reduction (-7.3%, p = 0.062) of UPDRS total scores was also observed. The increased availability of striatal D(2) receptors, is likely to be caused by drug induced modification of receptors expression. This hypothesis is consistent with previous experiments, indicating an increase in striatal D(2) receptors in rats treated with amantadine or other non competitive NMDA antagonists and suggests that the neo-synthesis of D(2) receptors may represent a reinforcing mechanism of drug efficacy.
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PMID:New perspectives on neurochemical effects of amantadine in the brain of parkinsonian patients: a PET - [(11)C]raclopride study. 1237 60


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