Desmopressin for the Treatment of Orthostatic Hypotension and Excessive Nighttime Urination in Parkinson’s Disease

This study is for people with Parkinson's disease who also have two specific problems: low blood pressure when they stand up (orthostatic hypotension), which can cause dizziness or fainting, and needing to urinate two or more times during the night (nocturia). Researchers are testing whether a medicine called desmopressin, taken by mouth, can help with both of these problems. The study runs for 8 weeks, and participants will take either the real medicine or a matching placebo (dummy pill) during different parts of the study, so everyone gets to try both. You may be eligible if: - You are between 30 and 85 years old - You have been diagnosed with Parkinson's disease - You experience low blood pressure when you stand up - You need to empty your bladder 2 or more times each night You may NOT be eligible if: - You have a history of kidney failure, congestive heart failure, or liver cirrhosis - You have a history of low blood sodium (hyponatremia) - You have dementia Talk to your doctor about whether this trial might be right for you.