The End for Levodopa Phobia: New Study Shows Sinemet is a Safe Initial Therapy for Treatment of Parkinson’s Disease
You can find out more about NPF's National Medical Director, Dr. Michael S. Okun, by also visiting the NPF Center of Excellence, University of Florida Center for Movement Disorders & Neurorestoration. Dr. Okun is also the author of the Amazon #1 Parkinson's Best Seller 10 Secrets to a Happier Life
In November 2011 we wrote about an important phenomenon called levodopa phobia, or avoidance of dopamine as a treatment for Parkinson’s disease. Many Parkinson’s disease patients and family members have been unnecessarily alarmed by the continuing reports that Sinemet and/or Madopar (European Sinemet) may accelerate disease progression, and that doses and drug intervals should be limited. These reports have unfortunately been fueled by sparse human evidence. Patients need to be aware that dopamine replacement therapies such as Sinemet and Madopar remain the single most effective, and single most important treatment for Parkinson’s disease worldwide. This month’s “What’s Hot” column will update the previous 2011 column, and focus on the new evidence published in the Lancet this month by the PD MED Collaborative Group.
Neurology previously published an article in 2011 citing that there was important evidence that dopamine replacement therapy is not toxic, and does not accelerate disease progression. Parkkinen and colleagues at Queen Square in London examined pathology in 96 post-mortem Parkinson’s disease brains, and paired the tissue with clinical information including levodopa use. The study concluded that in the human condition “chronic use of L-dopa does not enhance progression of Parkinson’s pathology.”
In an accompanying editorial, two prominent neurologists in the field pointed out that there “remains lingering concerns as to whether levodopa is toxic to dopamine neurons and accelerates the degenerative process.” The science quoted to support these claims has included levodopa undergoing auto-oxidation, and forming reactive oxygen species and toxic protofibrils. Additionally, the science includes a classical experiment that showed when levodopa was mixed with brain cells placed in a dish, there was toxicity. The research, however, has fallen short in demonstrating toxicity of the drug in the human form of Parkinson’s disease. There now exist broad levels of evidence from many studies across many countries (including most recently the ELLDOPA study) that levodopa is extremely beneficial to the human patient, and that levodopa has had a positive effect on disease course. Sinemet was recently reported as the most commonly administered drug among 7000+ patients being followed longitudinally in the National Parkinson Foundation Quality Improvement Initiative study. Expert practitioners who reported in this database utilized levodopa more than any other drug-- including dopamine agonists, and they used levodopa more (not less) as disease durations increased.