[Changes in the nigrostriatal dopamine receptor compartment after continuous dopaminergic infusions in Parkinson disease].
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.
Baronti
F
F
Dipartimento di Scienze Neurologiche, Università La Sapienza, Roma.
Ruggieri
S
S
Mouradian
M M
MM
Bonamartini
A
A
Bocciarelli
P
P
De Pandis
M F
MF
Chase
T N
TN
Agnoli
A
A
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
D011954:Receptors, Dopamine; D007980:Levodopa
Modificazioni del compartimento recettoriale dopaminergico nigrostriatale dopo infusione dopaminergica continua nel morbo di Parkinson.