The treatment of Parkinson's disease: current concepts and rationale.

The recent advances in the treatment of Parkinson's disease have made for significant improvements in the quality of life and mortality rate of those who suffer from this neurodegenerative disease. At the same time, the number of options and the complexity of multi-drug regimens have posed a great challenge for the clinician caring for the patient with Parkinson's disease. Though there are still many questions to be answered in regard to the potential neuroprotective effects of several medications, a few general rational treatment plans can be outlined. In patients requiring treatment in the early stages of the disease, especially with a predominance of tremor, anticholinergics or amantadine should be considered initially. At this point, it would be reasonable to add selegiline for both therapeutic and possible neuroprotective effects. As a patient becomes more affected by the disease and additional therapy is necessary, starting either a dopamine agonist or levodopa would be a rational choice. Continuation of selegiline and, possibly, amantadine for neuroprotective reasons should be contemplated. Titration in levodopa therapy (with controlled-release or standard levodopa) to higher levels should prompt addition of a dopamine receptor agonist if one has not been started previously. Conversely, if a patient is receiving only a dopamine receptor agonist and is becoming progressively disabled, levodopa should be added to the regimen. Fluctuations in motor abilities may be improved further by the use of a COMT inhibitor. Patients with uncontrollable motor fluctuations should be considered for surgery. Undoubtedly, the coming years will bring more treatment options and more evidence on which sequences and combinations of therapies are the most beneficial. Differences in efficacy and adverse effects for each patient must be taken into consideration when outlining and carrying out a treatment plan. By using a rational approach to the treatment of Parkinson's disease, with the above guidelines in mind, the patient should be able to enjoy a good quality of life and level of function for many years.