Fortunately, physicians have other treatment choices for particular symptoms or stages of the disease. They are generally less effective than levodopa in controlling rigidity and bradykinesia. Side effects may include paranoia, hallucinations, confusion, dyskinesias, nightmares, nausea and vomiting. Recent studies supported by the National Institute of Neurological Disorders and Stroke have shown that the drug delays the need for levodopa therapy up to a year or more. When selegiline is given with levodopa, it appears to enhance and prolong the response to levodopa and thus may reduce wearing-off fluctuations.
Dopamine then accumulates in the surviving nerve cells.
Some physicians, but not all, favor starting all parkinsonian patients on selegiline because of its possible protective effect. Researchers are still trying to answer questions about selegiline use, such as how long does the drug remain effective and does long-term use have any adverse effects. Evaluation of the long-term effects will help determine selegiline's value for all stages of the disease. These drugs were the main treatment for Parkinson's disease until the levodopa's introduction. Their benefit is limited, but they may help control tremor and rigidity.