Melatonin in Parkinson’s disease

Abstract

JO N 2788 advanced and speculates that the beneficial effects of melatonin administration might have been associated to correction of this hypothetical circadian abnormality in our subjects. Although we agree that Dr. Fertl’s explanation for our findings deserves further investigation, there are some aspects related to this hypothesis that we would like to address. Phase advance in PD can be influenced by drug therapy but also by age [3], disease severity, pattern of daily activities [4] and associated comorbidities, such as depressive symptoms and daytime sleepiness [5]. Thus, a clear demonstration of an association between levodopa therapy and phase advance in these patients must take into careful consideration all these variables, which, to our knowledge, has not yet been done. We disagree from Dr. Fertl when she states that our patients were on “relatively high mean daily dose of levodopa”. On the contrary, we believe that 600 mg/d is a modest dose, in view of the current recommendations encouraging levodopa therapy to reduce motor disability [6]. Interestingly, patients without fluctuations and on lower doses of levodopa showed a trend for more sleep fragmentation in our study. Finally, given the evidence that melatonin is associated with nigrostriatal protection, reduced Camila Andrade Mendes Medeiros Pedro Felipe Carvalhedo de Bruin Livia Ariane Lopes Maria Cecilia Magalhaes Maria de Lourdes Seabra Veralice Meireles Sales de Bruin