Chronic levodopa and renal function.

Abstract

Renal function studies were performed in seventeen patients, under metabolic ward conditions, before the initiation of therapy with levodopa. These studies were repeated during the first two to three weeks of treatment and, again, after one to two years of chronic therapy. There were no significant differences between the results of pre- and post-therapy studies, except that the blood urea nitrogen was slightly, but significantly, elevated in the nine patients who had been on the drug for one to two years. During the early weeks of treatment, there was an insignificant trend towards hypotension and increased excretion of sodium. This did not persist in those patients followed for one to two years after the initiation of treatment. Glomerular filtration rate, as measured by an endogenous method, was unchanged by chronic therapy with levodopa. These results are in contrast to the acutely increased glomerular filtration rate, as measured by an exogenous method, and the increased sodium excretion following a single dose of levodopa or dopamine.