What is the recommended dosage and usage of Domperidone (generic name) for treating nausea and vomiting?

Domperidone Dosing and Usage for Nausea and Vomiting

Start domperidone at 10 mg three times daily (before meals) for treating nausea and vomiting, with a maximum dose of 20 mg three to four times daily if needed, though the lower dose is preferred to minimize cardiac risks. 1

Standard Dosing Regimen

• Initial dose: 10 mg orally three times daily, taken before meals 1
• Maximum dose: 20 mg three to four times daily for refractory symptoms 2, 1
• Timing: Administer before meals and at bedtime for optimal effect 3
• The starting dose of 10 mg TID is preferred over higher doses due to safety considerations related to QT prolongation risk 1

Clinical Applications and Efficacy

Domperidone is effective across multiple conditions causing nausea and vomiting:

• Gastroparesis: Improves overall symptom severity, early satiety, and postprandial fullness, with symptom improvement typically beginning by day 3 of treatment 4
• Chemotherapy-induced nausea/vomiting: Use 20 mg three to four times daily as part of antiemetic regimens 2
• Functional dyspepsia: Reduces nausea, vomiting, and upper abdominal discomfort 1, 3
• Refractory cases: Add domperidone to serotonin antagonists and corticosteroids when first-line therapy fails 2, 1

The drug works as a peripheral dopamine D2-receptor antagonist that does not readily cross the blood-brain barrier, resulting in significantly fewer extrapyramidal side effects compared to metoclopramide 1, 5

Duration of Action

• Domperidone provides symptom relief for approximately 7-14 hours per dose, with a plasma half-life of 7.5 hours 1
• This pharmacokinetic profile supports the three-times-daily dosing schedule 1

Critical Safety Considerations

Cardiac monitoring is essential due to the risk of QT prolongation and torsades de pointes, particularly at higher doses:

• Avoid exceeding 10 mg three times daily when possible to minimize cardiac risks 1
• ECG monitoring may be warranted in patients with other QT prolongation risk factors (electrolyte abnormalities, concurrent QT-prolonging medications, cardiac disease) 1
• Intravenous administration carries higher cardiac risk and should be avoided 2

Common Side Effects

Reported adverse effects include:

• Palpitations (most concerning cardiac symptom) 4
• Headache 4
• Breast tenderness and menstrual irregularities (due to dopamine antagonism affecting prolactin) 4
• Dizziness, drowsiness, constipation (less common) 4

Advantages Over Metoclopramide

Domperidone is strongly preferred over metoclopramide for extended therapy due to its superior safety profile:

• Significantly lower risk of extrapyramidal side effects (dystonia, akathisia, tardive dyskinesia) 1, 6
• Does not worsen symptoms in Parkinson's disease patients 1
• Preferred in pediatric patients for the same safety reasons 1
• The American Gastroenterological Association recommends domperidone as an alternative to metoclopramide for long-term use 1, 6

Treatment Duration and Monitoring

• Clinical trials demonstrate efficacy over 6-week treatment periods 4, 3
• Symptom improvement typically begins within 3 days of initiating therapy 4
• Regular monitoring for cardiac symptoms and movement disorders is recommended during ongoing therapy 6

Regulatory Status

• Domperidone is not FDA-approved in the United States but is widely available in Canada, Mexico, and Europe 2
• In the U.S., it requires an investigational new drug application protocol for use 1
• Despite lack of FDA approval, it is recommended by the American Gastroenterological Association for gastroparesis treatment 1