Henry P. Parkman, Zubair Malik, Ron Schey, Robert S. Fisher
BACKGROUND: Domperidone is used to treat refractory symptoms of gastroparesis. There is awareness about the risks and benefits of using domperidone; however, studies have primarily been short-term. AIM: To review treatment results with domperidone with focus on long-term efficacy and side effects. METHODS: Patients with gastroparesis symptoms who entered our FDA IND, IRB-approved domperidone protocol between 2005 and 2025 were treated with oral domperidone 10 mg 3-4 times daily and followed every 2 months for the first year, then every 6 months. Patients completed Patient Assessment of Upper GI Symptoms (PAGI-SYM) and Clinical Patient Grading Assessment Scale (CPGAS; +3 = great deal better, 0 = no change). RESULTS: 827 patients (64% idiopathic, 22% diabetic, 6% postsurgical, 5% atypical) participated; delayed gastric emptying in 86%, normal in 13%, and rapid in 1%. 298 patients have continued domperidone for 7.6 ± 6.4 years with a dose of 36 ± 20 mg per day. The CPGAS benefit score averaged 2.3 ± 0.9 (~"moderately better"). There were improvements in symptoms, particularly nausea, postprandial fullness, and loss of appetite. 529 patients stopped domperidone treatment; lack of efficacy (114 patients), side effects (100), switching to another treatment (42), cost (26), and the remainder lost to follow up. Most common side effects for stopping DOM were palpitations (20 patients), prolonged EKG QTc (13), chest pain (11), diarrhea (10), headache (9), dizziness (8), and lactation (8). CONCLUSIONS: In this study of patients treated with long term domperidone for symptoms of gastroparesis, 298 of 827 (36%) patients continued treatment for a mean of 7.6 years with patients reporting being moderately better. Thus, in select patients, domperidone treatment is an effective long-term treatment for symptoms of gastroparesis, able to be safely administered with careful patient monitoring.