(1) We read with interest the article by Churchyard et al 1 showing that selegiline in combination with levodopa was associated with significant impairment of the normal reflex responses controlling blood pressure to head up tilt and standing. It was suggested by the authors that this could be one explanation of the finding of increased mortality in the combined levodopa/selegeline arm of the Parkinson’s Disease Research Group of the United Kingdom trial.2 We are currently conducting a study investigating the cardiovascular reflexes in patients recruited from a community disease register for Parkinson’s disease, diagnosis being based on identical clinical diagnostic criteria to the reported study. Patients were excluded from the study if they were known to have diseases associated with impaired autonomic system function or if they were currently being treated with drugs other than those for Parkinson’s disease. We have identified 27 such patients, five receiving selegiline and levodopa and 22 receiving levodopa. With similar techniques and equipment as the authors we have measured orthostatic blood pressure at 1 minute, Valsalva ratio, and heart rate on standing (30:15 ratio). Age, sex, duration of disease, Webster scale, and daily levodopa dose did not differ significantly between the group of patients on levodopa alone and on levodopa and selegiline combined (table). There was no significant difference in the results of autonomic function testing between the two groups with analysis of varience (ANOVA) andt tests. Both groups of patients showed falls in blood pressure on standing and this did not seem to be more pronounced in the group on levodopa plus selegiline compared with patients on levodopa alone. This finding is surprising given the much lower dose of levodopa prescribed in our study compared with that of Churchyard et al. However, our failure to show significant hypotensive interaction between …