Exploratory pilot study of exogenous sustained-release Melatonin on nocturia in Parkinson's Disease.

INTRODUCTION Nocturia is one of the commonest non-motor symptoms in Parkinson's disease (PD). Nocturia has evolved from being understood as a symptom of urological disorders or neurogenic bladder dysfunction to being considered as a form of circadian dysregulation. Exogenous melatonin is known to help circadian function and can be an effective strategy for nocturia in PD. METHODS In this open label single-site exploratory phase 2 pilot study, adults with PD and nocturia underwent assessments using standardised questionnaires, urodynamics studies and a bladder scan. This was followed by completion of a frequency volume charts (FVC) and two weeks sleep diary. Sustained-release melatonin 2mg was then administered once nightly for six weeks. A repeat assessment using questionnaires, the FVC and sleep diary was performed whilst on treatment with melatonin. Companion or bed partners filled in sleep questionnaires to assess their sleep during the intervention. RESULTS 20 patients (12 males; mean 68.2 (SD=7.8) years; mean PD duration 8.0 (±5.5) years with PD reporting nocturia were included. Administration of melatonin was associated with a significant reduction in the primary outcome bother related to nocturia measured using the International Consultation on Incontinence Questionnaire Nocturia (ICIQ-N) (p=0.01), number of episodes of nocturia per night (p=0.013) and average urine volume voided at night (p=0.013). No serious adverse events were reported. No significant improvement was noted in bed-partner sleep scores. CONCLUSION In this preliminary open-label study, administration of sustained-release melatonin 2mg was found to be safe for clinical use and was associated with significant improvements in night-time frequency and nocturnal voided volumes in PD patients.