Revisiting the Incidence of Tardive Dyskinesia With Oral Metoclopramide Use: A Real‐World Epidemiology Study (2011–2020)

BACKGROUND: Gastroparesis is a debilitating disorder with limited treatment options, and metoclopramide remains the only FDA-approved pharmacologic therapy. Concerns about metoclopramide-induced tardive dyskinesia (TD) are based on older studies with inconsistent incidence estimates (1%-15%). A reassessment of metoclopramide's TD risk is needed. METHODS: A retrospective cohort study using the MarketScan Research database analyzed TD incidence in adults (2011-2020) with at least 12 months of medical and pharmacy benefits. TD rates were compared among metoclopramide-treated gastroparesis patients, those untreated, and the general population. Poisson regression models adjusted for person-years (p-yrs) at risk. KEY RESULTS: The incidence of TD among metoclopramide-treated gastroparesis patients was 159.4 per 100,000 p-yrs (0.37%), notably lower than guideline estimates (1%-15%). Comparatively, TD incidence was 121.3 (0.26%) in untreated gastroparesis patients, 51.4 (0.12%) among all metoclopramide users, and 7.6 (0.02%) in the general population. Higher TD rates were observed in older adults (≥ 65 years), females, and in patients with prolonged metoclopramide use, diabetes, psychiatric conditions, Parkinson's disease, or concurrent use of dopamine receptor-blocking agents. Adjusted analyses found no significant independent association between metoclopramide use and increased TD risk in gastroparesis patients. CONCLUSIONS & INFERENCES: TD incidence is uncommon with metoclopramide use and lower than previously estimated in gastroparesis patients. These findings suggest metoclopramide may be a viable treatment option and warrant a reassessment of its risk-benefit profile in gastroparesis management.