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

INTERVENTION: Subjects will start with either nightly placebo or oral desmopressin for three weeks. After a washout period of one week of no medication, they will then switch to the therapy they have not tried for another three weeks. Subjects taking desmopressin will begin with a 100 mcg nightly dose. If this is tolerated, after one week they will increase to 200 mcg nightly, which they will take for two weeks. CONDITION: Nocturia Orthostatic Hypotension Parkinson's Disease PRIMARY OUTCOME: Improvement of at least 2 points on the COMPASS‐OD survey, which assesses for symptoms of low blood pressure. Number of nocturnal bladder voids as measured by a diary SECONDARY OUTCOME: Improvement in sleep as measured by a survey (Epworth Sleepiness Scale) INCLUSION CRITERIA: Parkinson's disease Orthostatic hypotension (blood pressure drop with standing) A need to empty the bladder 2 or more times at night