Prevention and management of late stage complications in Parkinson's disease

The major complications of therapy in PD are motor, autonomic and psychiatric. Motor complications may be associated with altered striatal bioavailability of levodopa, and may in part respond to changes in timing of drug administration, redistribution of dietary protein and the use of controlled-release preparations. Since long-term complications seem to be associated with higher cumulative doses of levodopa, the early use of adjunctive agents such as deprenyl and/or dopamine agonists is encouraged. Autonomic effects include impaired bladder and bowel function, impotence and postural hypotension. If conservative measures are ineffective, pharmacotherapy with domperidone, fludrocortisone, indomethacin or adrenergic agents may be required. Depression in PD is associated with decreased levels of noradrenaline and 5-HT and responds to tricyclic antidepressants. Drug-induced psychosis reflects stimulation of mesolimbic-cortical dopamine receptors. Alternatives include reduction of medication, the use of atypical neuroleptics (which may act at novel subtypes of the dopamine receptor) and electroconvulsive therapy.