Sixty-nine patients with Parkinson's disease were randomly allocated in a trial to compare the therapeutic effects of levodopa and amantadine. The patients were assessed clinically and scored by occupational therapy tasks and degrees of disability. Both drugs were used for 2 months; in the first 4 weeks the doses were gradually increased to 400 mg of amantadine or 4 g of levodopa respectively, ...

Levodopa is the principal agent in the treatment of Parkinson’s disease (PD). Unfortunately the therapeutic benefits are optimal only in the early stages of the disease, with long-term use associated with motor complications such as levodopa-induced dyskinesia (LID). Risk factors associated with the development of LID are generally accepted to involve the degree of dopamine (DA) denervation in ...

Dopamine has been hypothesized to modulate response inhibition. To test this hypothesis, we used functional magnetic resonance imaging (fMRI) to measure the effects of the dopamine prodrug levodopa on the brain responses to a well-validated response inhibition task (go/no-go, or GNG). Since abnormalities of response inhibition and dopamine have been thought to underlie tics and other symptoms o...

In 1993, the last AAN Practice Parameter on medical treatment of Parkinson's disease (PD) concluded that levodopa was the most effective drug for management of this disorder. Since then, a number of new compounds including non-ergot dopamine agonists (DA) and sustained-release levodopa have been released and studied. Thus, the issue of treatment in de novo PD patients warrants reexamination. Sp...

1. The intra-arterial blood pressure responses to Valsalva’s manoeuvre and postural change were investigated as indices of cardiovascular reflex activity in seventeen Parkinsonian patients on maximally tolerated doses of L( -)-dopa (levodopa) and repeated in nine patients on levodopa with an extracerebral decarboxylase inhibitor, L-alpha methyldopahydrazine. The results were compared with contr...

Twenty-seven Parkinsonism patients and 31 controls, matched for age and verbal IQ, were tested on an objectively scored personality test (Minnesota Multiphasic Personality Inventory) at the beginning of the patients' levodopa therapy and three months later. Patients, but not the controls, were retested after 15 months of levodopa treatment. The patients, all of whom were intact intellectually, ...

Motor fluctuations complicate the treatment of patients with Parkinson's disease receiving levodopa. Extended-release carbidopa-levodopa has a pharmacokinetic profile that provides a more continuous levodopa serum concentration. Patients taking this formulation can expect longer duration of action and fewer doses per day, similar clinical improvement when compared to other levodopa formulations...

the aim of most pharmacotherapy for Parkinson’s disease (PD). The theoretical background to CDS is that the physiological striatal dopaminergic stimulation is constant and that oral therapy with levodopa in PD can replace dopaminergic stimulation only in an intermittent, non-physiological manner.1,2 This pulsatile stimulation of the dopamine receptors is thought to contribute to the development...

Fifteen of 23 pathologically confirmed cases of multiple system atrophy (MSA) showed some initial response to levodopa and eight of these remained at least partially responsive at the time of death. Eleven developed motor oscillations, and drug-induced dyskinesias, often involving the face and jaw, were also seen in 11 cases. Acute levodopa and apomorphine challenges were administered to 11 pat...

A simple and sensitive methodology for the simultaneous determination of levodopa and carbidopa in pharmaceutical samples is described. The method combines the advantages of fluorescence with partial least-squares (PLS) analysis, and requires no previous separation steps. The developed method is based on the oxidation of levodopa and carbidopa by cerium(IV) in a sulfuric acid medium and monitor...