For this reason, much research in Parkinson's disease today focuses on how to forestall disability and maintain or improve function over the long-term. New combination druga and surgical procedures available. There is considerable differences of opinion concerning whether the patient should be started immediately on drugs or wait till the disease has progressed. As noted, levodopa loses effectiveness and develops long term complications after 4-5 years. So, the doctors do not want to lose the window of opportunity.
Some doctors keep levodopa at very low levels by using other medicines in combination.
Newer drugs are available that provide earlier protection before levodopa therapy. Degeneration of the substantia nigra in Parkinson's disease causes a dopamine deficiency in the striatum. They are a new class of medications that slow the peripheral metabolism of levodopa and thereby make more of the drug available for transport across the blood-brain barrier over a longer period. Selegiline increases dopamine activity in the brain by inhibiting its metabolism. Dopamine agonists provide symptomatic benefit by directly stimulating post-synaptic striatal dopamine receptors.