Melatonin for Nocturia in Parkinson's Disease

This is an an open label clinical trial of sustained-release Melatonin 2mg once daily for 12 weeks in patients with Parkinsons's Disease reporting nocturia, defined as getting up regularly at night \> twice to pass urine. The primary objective of this study is to evaluate the effects of exogenous melatonin on bother related to nocturia. Secondary objectives are to evaluate: 1) Mean night time urinary frequency 2)Volume of urine voided at night 3)Incontinence and other lower urinary tract symptoms (LUTS) 3)Quality of sleep 4) Quality of life 5) Sleep disturbance of partners 6)Safety