Incidence of Parkinsonism after Treatment with Metoclopramide

Abstract

Metoclopramide, which is commonly used in general internal practice for gastrointestinal disorders, is known to induce parkinsonism at a low but as yet undetermined rate. We studied the incidence of parkinsonism after the treatment with metoclopramide. Two (1.3%) of the 150 patients orally administered the agent for more than 2 weeks developed parkinsonism in 1982. The actual incidence, however, was estimated to be 0.26% since they were two among all the parkinsonian patients we have treated for the past 5 years. Both of these patients were over 70 years of age. However, some patients over 80 who underwent long-term metoclopramide treatment did not develop the disease, suggesting that individual factors are largely involved in the pathogenesis.