Effect of levodopa on thyroid function and prolactin release. A study in patients with Parkinson's disease.

Abstract

• Patients with Parkinson's disease who received a regimen of levodopa at levels that gave good clinical results did not have impaired thyroid function. The response of thyrotropin to intravenous administration of protirelin in these patients was not impaired by long-term levodopa therapy, but the prolactin response at 60 minutes was suppressed only in women. The response of prolactin to protirelin stimulation became similar to that found in both treated and untreated