Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tolcapone, a central and peripheral catechol O-methyltransferase (COMT) inhibitor, reduces the conversion of L-Dopa into 3-O-methyl-Dopa (3-OMD), thus leading to more stable and sustained L-Dopa plasma levels. This study was designed to evaluate the effects of acute and 6-week tolcapone administration on L-Dopa pharmacokinetics and pharmacodynamics in Parkinson's disease (PD) patients with predictable motor fluctuations. Tapping test, walking time, and tremor, as well as L-Dopa and 3-OMD plasma levels, were assessed before and for 5 hours after the administration of a single L-Dopa dose, alone or in combination with 200 mg tolcapone, in seven patients with PD. This clinical and pharmacokinetic study was repeated after 6 weeks of tolcapone therapy (200 mg three times daily). It was observed that tolcapone, after both acute and chronic administration, prolonged the motor improvement induced by L-Dopa. As a result, at week 6 of tolcapone therapy, the daily hours spent "off" were significantly decreased. Tolcapone significantly increased the area under the curve of L-Dopa plasma levels by slowing down the elimination of L-Dopa from plasma, whereas the maximal concentration of L-Dopa was not modified. 3-OMD levels decreased significantly after acute tolcapone administration, and after 6 weeks of tolcapone therapy, they were approximately one sixth of pre-tolcapone values. The data confirm that tolcapone decreases L-Dopa clearance and prolongs motor response in PD patients with motor fluctuations, and that this effect is maintained after 6 weeks of tolcapone therapy.
 ...
PMID:Pharmacokinetics and pharmacodynamics of L-Dopa after acute and 6-week tolcapone administration in patients with Parkinson's disease. 1004 30

Parkinson's disease is a progressive degenerative disorder of the central nervous system. The hallmark physical signs are tremor, rigidity and bradykinesia. Idiopathic Parkinson's disease is caused by the progressive loss of dopaminergic neurons in the substantia nigra and nigrostriatal pathway of the midbrain. Secondary parkinsonism may be caused by certain drugs (e.g., metoclopramide and haloperidol) or by cerebrovascular disease (e.g., multiple lacunar strokes). The disease can usually be diagnosed based on the history and physical findings. Dopamine replacement is still considered the most efficacious treatment for Parkinson's disease, but dopamine agonists, formerly prescribed only as adjunctive therapy, are emerging as useful initial therapy. Other pharmacologic treatments include drugs that inhibit dopamine-metabolizing enzymes (monoamine oxidase-B and catechol O-methyltransferase). Injections of botulinum toxin can be helpful in patients with associated dystonia or blepharospasm. Surgery may be indicated for certain patients or when symptoms do not respond to medical therapy. Additional adjunctive therapies include physical therapy, nutritional counseling and techniques to help patients manage emotional and cognitive changes related to the disease.
 ...
PMID:Update on Parkinson's disease. 1022 2

Parkinson's disease is a common neurodegenerative disorder that can cause significant disability and decreased quality of life. The cardinal physical signs of the disease are distal resting tremor, rigidity, bradykinesia, and asymmetric onset. Levodopa is the primary treatment for Parkinson's disease; however, its long-term use is limited by motor complications and drug-induced dyskinesia. Dopamine agonists are options for initial treatment and have been shown to delay the onset of motor complications. However, dopamine agonists are inferior to levodopa in controlling motor symptoms. After levodopa-related motor complications develop in advanced Parkinson's disease, it is beneficial to initiate adjuvant therapy with dopamine agonists, catechol O-methyltransferase inhibitors, or monoamine oxidase-B inhibitors. Deep brain stimulation of the subthalamic nucleus has been shown to ameliorate symptoms in patients with advanced disease. Depression, dementia, and psychosis are common psychiatric problems associated with Parkinson's disease. Psychosis is usually drug induced and can be managed initially by reducing antiparkinsonian medications. The judicious use of psychoactive agents may be necessary. Consultation with a subspecialist is often required.
 ...
PMID:Parkinson's disease: diagnosis and treatment. 1955 11

Parkinson disease is a progressive neurologic disorder afflicting approximately 1 percent of Americans older than 60 years. The cardinal features of Parkinson disease are bradykinesia, rigidity, tremor, and postural instability. There are a number of neurologic conditions that mimic the disease, making it difficult to diagnose in its early stages. Physicians who rarely diagnose Parkinson disease should refer patients suspected of having it to physicians with more experience in making the diagnosis, and should periodically reevaluate the accuracy of the diagnosis. Treatment is effective in reducing motor impairment and disability, and should be started when a patient begins to experience functional impairment. The combination of carbidopa and levodopa is the most effective treatment, but dopamine agonists and monoamine oxidase-B inhibitors are also effective, and are less likely to cause dyskinesias. For patients taking carbidopa/levodopa who have motor complications, adjunctive therapy with a dopamine agonist, a monoamine oxidase-B inhibitor, or a catechol O-methyltransferase inhibitor will improve motor symptoms and functional status, but with an increase in dyskinesias. Deep brain stimulation is effective in patients who have poorly controlled symptoms despite optimal medical therapy. Occupational, physical, and speech therapy improve patient function. Fatigue, sleep disturbances, dementia, and depression are common in patients with Parkinson disease. Although these conditions are associated with significantly lower quality of life, they may improve with treatment.
 ...
PMID:Parkinson disease: an update. 2413 84