Acute orthostatic hypotension when starting dopamine agonists in Parkinson's disease

Objective: To study the frequency and severity of acute orthostatic hypoten sion (OH) in patients with Parkinson's disease who are starting dopamine ag onist therapy. Patients and Methods: In the context of an outpatient clinical practice, 29 consecutive patients with Parkinson's disease who were starting dopamine a gonist therapy were brought into the clinic for their first dose of agonist . After a baseline supine and standing blood pressure assessment, patients were given a test dose of either pergolide mesylate (0.025, 0.05, 0.125, or 0.25 mg), pramipexole dihydrochloride (0.125 mg), or ropinirole hydrochlor ide (0.125 or 0.25 mg). At 3 selected times, blood pressure readings were r epeated in the supine and standing positions. Main Outcome Measure: Orthostatic hypotension was defined as a drop in eith er systolic blood pressure of more than 25 mm Hg or diastolic pressure of m ore than 10 mm Hg. Patients with OH before the administration of the dopami ne agonist were excluded. Results: Ten subjects (34%) met the criteria for acute OH. There was no evi dence that OH was related to the use of a specific dopamine agonist or the concurrent use of levodopa. Of the patients who met the criteria for OH, on ly 3 (30%) had symptoms of OH, such as lightheadedness or general malaise. Conclusions: Acute OH occurs frequently when starting dopamine agonist ther apy in Parkinson's disease, but is frequently not appreciated by patients. Knowledge of acute blood pressure responses may be useful when making decis ions regarding agonist titration schedules in clinical practice.