nitrophenols and Movement-Disorders

Although levodopa remains the most effective drug for the symptomatic treatment of Parkinson's disease (PD), there are significant limitations to its chronic use. Growing preclinical and clinical evidence suggests that the severity of motor fluctuations is influenced both by PD severity and pulsatile stimulation of striatal dopamine receptors. Current management of motor fluctuations is based primarily on strategies to prolong the effects of dopaminergic stimulation. This prolongation is accomplished either through the use of long-acting dopaminergic drugs or prolonging of the effects of levodopa. During the past decade, the armamentarium of dopamine agonists increased and agents that prolong the plasma half-life of levodopa became available. Furthermore, recent clinical trials provide evidence-based approaches to improve the management of motor fluctuations in patients with advanced and early PD.

Topics: Apomorphine; Benzophenones; Cabergoline; Catechol O-Methyltransferase Inhibitors; Catechols; Dopamine Agonists; Ergolines; Humans; Levodopa; Movement Disorders; Nitriles; Nitrophenols; Parkinson Disease; Tolcapone

Movement disorders is a term applied for a heterogeneous group of diseases and syndromes sharing deficits of voluntary motor function or movement patterns. In clinical practice, the term movement disorders is usually employed to designate those syndromes and diseases that are linked to a pathology or dysfunction of cortico-basal ganglia circuits. The last years have witnessed a rapid expansion in our understanding of the etiological and pathophysiological factors underlying movement disorders such as Parkinson's disease or dystonia. The discovery of new gene mutations is bound to give rise to new insights into the molecular pathogenesis of movement disorders related to neurodegenerative processes. It is already becoming apparent that pathological protein aggregation may be a common link in the neuronal degeneration underlying such diverse entities as spinocerebellar ataxia, idiopathic torsion dystonia and Parkinson's disease. So far, these new findings have not been translated into new forms of symptomatic or preventive therapies. Nevertheless, symptomatic treatment of movement disorders, as evident in the field of Parkinson's disease, is one of the most rewarding and innovative areas of neurological therapy.

Topics: Antiparkinson Agents; Benzophenones; Catechol O-Methyltransferase Inhibitors; Catechols; Dopamine Agonists; Drug Therapy, Combination; Electric Stimulation Therapy; Enzyme Inhibitors; Globus Pallidus; Humans; Movement Disorders; Mutation; Nitriles; Nitrophenols; Parkinson Disease; Subthalamic Nucleus; Tolcapone

The effects of acute catechol-O-methyltransferase (COMT) inhibition on L-DOPA pharmacokinetics were studied in 10 parkinsonian subjects on stable doses of L-DOPA/carbidopa and selegiline. Tolcapone, a reversible COMT inhibitor, was administered in four single ascending doses (50-800 mg) randomly paired with placebo. Serial plasma concentrations of L-DOPA and its metabolites were measured, and patient diaries and clinical ratings of dyskinesia were completed every 30 min for 6 h. Tolcapone increased the area under the curve of the plasma L-DOPA concentration versus time curve and decreased the accumulation of homovanillic acid. COMT inhibition increased "on" time and the duration of dyskinesia without affecting the maximal amplitude of dyskinesia. Tolcapone may be a useful adjunct to L-DOPA/carbidopa.

Topics: Aged; Antiparkinson Agents; Benzophenones; Carbidopa; Dose-Response Relationship, Drug; Humans; Levodopa; Movement Disorders; Nitrophenols; Parkinson Disease; Selegiline; Tolcapone

Topics: Abnormalities, Drug-Induced; Anticonvulsants; Cats; Electrophysiology; Hypnotics and Sedatives; Methaqualone; Mice; Movement Disorders; Nitrophenols; Pharmacology; Quinolizines; Rabbits; Rats; Research; Toxicology