Comparison of motor response to apomorphine and levodopa in Parkinson's disease.

Abstract

The magnitude and pattern of motor responses to single doses of subcutaneous apomorphine and oral levodopa were compared in 14 patients with Parkinson's disease. Although apomorphine produced much shorter motor responses than levodopa, the quality of response to the two drugs was virtually indistinguishable. These clinical observations support the notion that integrity of striatal post-synaptic dopamine receptors is a key determinant of responsiveness to dopaminergic treatment in Parkinson's disease.

Apomorphine: An underutilized therapy for Parkinson's disease

“…It was the first dopaminergic drug ever used in this condition and its efficacy parallels that of the present "gold standard" of the drug treatment of the PD, L-dopa. 35,36 As a result of its peripheral dopaminergic side effects and potent emetic properties, apomorphine treatment requires temporary coadministration with a peripheral dopamine agonist (domperidone), but under such provisions it is as well tolerated as levodopa. Its major disadvantage is the need for parenteral application as a result of its high first-pass metabolism.…”

Worsening of levodopa-induced dyskinesias by motor and mental tasks

“…[13][14][15] Apomorphine, which stimulates D1 and D2 receptors, is known to produce similar responses as levodopa in patients with Parkinson's disease. 16 It can be reasonably expected that aggravation of dyskinesia after apomorphine administration could also be seen after levodopa administration.…”

Unilateral Battery Depletion in Parkinson’s Disease Patients Treated with Bilateral Subthalamic Nucleus Deep Brain Stimulation May Require Urgent Surgical Replacement

“…Chronic STN stimulation has been shown to decrease the magnitude of the short-duration response to levodopa [11] , which may explain our patients' lack of response. The exact mechanism behind this observation remains speculative, but the change in levodopa pharmacodynamics and appearance of fl uctuations and dyskinesias as PD progresses has been attributed to a hypersensitization of the dopaminergic receptors from intermittent administration of high doses of levodopa [12,13] . Chronic STN stimulation may reverse this process, either because of reductions in levodopa dosage, stimulation-induced plastic changes in the basal ganglia pathways or a combination of both [11,14] .…”