title: [Changes in the nigrostriatal dopamine receptor compartment after continuous dopaminergic infusions in Parkinson disease].
abstract: Motor fluctuations often complicate chronic levodopa treatment of Parkinson's disease. Pharmacologically, these phenomena are characterized by a progressive shortening of the duration of action of levodopa and a gradual narrowing of the range of "optimally effective" doses, able to improve parkinsonian akinesia without inducing abnormal involuntary movements. The effects of a continuous intravenous infusion of levodopa lasting 9 +/- 0.3 days on these clinical-pharmacological indices have been studied in 12 parkinsonian patients. Continuous infusion therapy gradually ameliorated motor fluctuations by more than 40%, and this improvement lasted for at least 6 days after resuming standard oral therapy. Moreover, levodopa duration of action was prolonged by about 30%, and the range of "optimally effective" dose was widened by about 50%. The above data suggest the possibility of plastic modifications of the pathogenetic mechanisms underlying motor fluctuations in Parkinson's disease, and a potential deleterious effect of intermittent oral therapy. Consequently, continuous dopaminergic stimulation, when used in the early stages of the disease, might theoretically have a prophylactic role on the development or worsening of motor fluctuations.
authors.affiliation: Dipartimento di Scienze Neurologiche, Università La Sapienza, Roma.
authors.forename: F
authors.initials: F
authors.lastname: Baronti
authors.forename: S
authors.initials: S
authors.lastname: Ruggieri
authors.forename: M M
authors.initials: MM
authors.lastname: Mouradian
authors.forename: A
authors.initials: A
authors.lastname: Bonamartini
authors.forename: P
authors.initials: P
authors.lastname: Bocciarelli
authors.forename: M F
authors.initials: MF
authors.lastname: De Pandis
authors.forename: T N
authors.initials: TN
authors.lastname: Chase
authors.forename: A
authors.initials: A
authors.lastname: Agnoli
mesh_terms: D000368:Aged; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007980:Levodopa / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology / Q000517:prevention & control; D010300:Parkinson Disease / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000502:physiology
chemical_list: D011954:Receptors, Dopamine; D007980:Levodopa
vernacular_title: Modificazioni del compartimento recettoriale dopaminergico nigrostriatale dopo infusione dopaminergica continua nel morbo di Parkinson.