March 6 (UPI) -- Researchers from the University of South Florida found in a retrospective analysis of clinical trial data that long-term use of monoamine oxidase type B, or MAO-B, inhibitors slows the clinical decline of patients with Parkinson's disease.
Previous studies have shown MAO-B inhibitors produce neuroprotective effects in cell culture and animal studies of Parkinson's disease, but clinical trials had shown mixed results and appeared not to have a significant effect on Parkinson's disease symptoms.
A secondary analysis of the NET-PD-LS1 clinical trial -- a multicenter, double blind, placebo-controlled study of 1,741 participants with early Parkinson's disease from March 2007 to July 2013 -- was conducted by researchers.
Roughly 784 of NET-PD-LS1 participants received a MAO-B inhibitor and were assessed using the Global Outcome, allowing researchers to consider a combination of five measurements of change from each participant's baseline measurements.
The new analysis revealed a significant link between longer duration MAO-B inhibitor use and slower clinical decline among Parkinson's patients, the researchers report.
"Earlier large trials aiming to evaluate potential disease modifying effects of MAO-B inhibitors unfortunately suffered from confounding motor effects or yielded conflicting results," Dr. Robert Hauser, of the Department of Neurology, Molecular Pharmacology and Physiology at the University of South Florida, said in a press release. "Our study suggests that we should not give up on the potential long term benefits of MAO-B inhibitors. A definitive, rigorous, long-term trial should strongly be considered."
The study was published in the Journal of Parkinson's Disease.