Levodopa (Sinemet) is the most effective medicine used to treat Parkinson’s disease. In fact, nearly everyone who has the disease will need it eventually. But there has long been a debate over whether it’s better to start the drug as soon as symptoms start—or hold out as long as possible to put off dealing with the risks associated with taking levodopa. New research now has the answer…
But first, some background…Parkinson’s disease (PD) is a progressive brain disease in which nerve cells in the brain that produce the chemical dopamine, a neurotransmitter needed to send signals between cells, gradually die. As the brain cells die, symptoms such as body tremors and slowed movement begin to interfere with daily activities. There is no cure for PD. Instead, symptoms are managed, typically with levodopa, a drug that converts to dopamine in the brain. Some research has found that starting levodopa soon after diagnosis—before symptoms curtail lifestyle—may slow progression of the disease. But other research has found that starting levodopa early actually may speed the loss of dopamine-producing brain cells…that the brain starts to depend more on drug-dopamine than on naturally produced dopamine. The resulting irregular brain levels of dopamine increase risk for dyskinesia, uncontrolled, jerky or writhing movement.
To learn more, researchers from University of Amsterdam in the Netherlands compared early versus delayed start of levodopa in 445 recently diagnosed PD patients whose symptoms were not severe enough to need the drug and who had never received any other treatment for their PD.
Half the patients were randomly assigned to receive a standard dose of levodopa for 80 weeks. The other half received a placebo for 40 weeks…and then levodopa for 40 weeks. Neither patients nor researchers knew which patients were in which group. Patients had their PD rated according to a standard test that measures mental and physical symptoms of the disease, as well as how much activities of daily life are affected. The average score for both groups at the start of the study was between 28 and 29 (out of a possible score of 176, with a higher score meaning more severe disease).
Results: The researchers expected to find that the early starters would have about a four-point advantage in their PD score at the end of the study. But in fact, there was no significant difference between the groups—a one-point improvement for early starters compared with a two-point improvement for late starters.
While it’s true that the study didn’t find any benefit to starting the drug early, it didn’t find any added risk in doing so either—88% of patients in the delayed group and 90% of patients in the early group had no evidence of dyskinesia.) These results indicate that it’s safe to start the drug whenever a patient (and his/her doctor) feels that it’s the right time.
Yet even without dyskinesia, levodopa still has side effects (including drowsiness, nausea, dry mouth, diarrhea, constipation, insomnia among others) that you may want to put off dealing with until the PD symptoms become truly bothersome. But at least now you have more choice.