Domperidone, also known by the brand name Motilium in some regions, is a medication classified as a dopamine antagonist. It works by blocking dopamine receptors in the chemoreceptor trigger zone, which helps reduce nausea and vomiting. It also affects dopamine receptors in the gut, increasing the movement of food through the digestive system. This makes it effective for several conditions.
Primary Uses of Domperidone
Domperidone is primarily used for its effects on the gastrointestinal system and to prevent vomiting. It is used to relieve nausea and prevent vomiting associated with various conditions. Its prokinetic effect is beneficial for individuals with gastroparesis, a condition causing slow stomach emptying. By increasing stomach muscle contractions, it helps move food into the small intestine, easing symptoms like bloating, nausea, and early fullness.
Less Common and Off-Label Uses
Beyond its primary uses, domperidone is also used in other situations.
- Lactation Support: It is sometimes used off-label to increase milk production in breastfeeding mothers. This is believed to be due to increased prolactin levels, a hormone vital for milk production. However, this use is controversial and not widely approved due to potential risks.
- Managing Medication Side Effects: Domperidone can help counteract gastrointestinal side effects like nausea and vomiting caused by other medications, such as some used for Parkinson's disease.
How Domperidone Works
Domperidone blocks dopamine receptors, particularly D2 receptors. In the chemoreceptor trigger zone, this prevents signals that cause nausea and vomiting. In the gut, blocking D2 receptors in smooth muscle and the enteric nervous system improves stomach and upper small intestine tone and motility. This accelerates gastric emptying and coordinates digestive movements.
Domperidone vs. Metoclopramide
Domperidone is often compared to metoclopramide, another antiemetic and prokinetic drug. Both block dopamine receptors but differ in their effects on the central nervous system.
| Feature | Domperidone | Metoclopramide |
|---|---|---|
| Blood-Brain Barrier | Does not readily cross | Readily crosses |
| CNS Side Effects | Lower incidence (e.g., tardive dyskinesia) | Higher incidence (e.g., tardive dyskinesia) |
| Primary Action | Peripheral dopamine receptor blockade | Peripheral and central dopamine receptor blockade |
| Cardiac Risks | Associated with QT prolongation and arrhythmias | Also associated with cardiac risks |
Domperidone crosses the blood-brain barrier less easily than metoclopramide, resulting in a lower risk of central nervous system side effects such as extrapyramidal symptoms and tardive dyskinesia. However, both medications have a risk of cardiac side effects, including QT prolongation and arrhythmias.
Safety Considerations and Side Effects
Domperidone can cause side effects like dry mouth, headache, and drowsiness. Other effects might include breast tenderness, digestive issues, and menstrual cycle changes.
A significant concern is its potential to affect heart rhythm. It is linked to an increased risk of serious ventricular arrhythmias and sudden cardiac death, especially at higher doses or in those with existing heart conditions. Because of these risks, many health authorities have restricted its use.
Contraindications
Domperidone should not be used by individuals with moderate to severe liver impairment, existing heart conditions, a history of QT interval prolongation, or electrolyte imbalances. It is also contraindicated in cases of gastrointestinal bleeding, obstruction, or perforation.
Important Precautions
Always inform your doctor about any medical conditions, especially heart problems, and all medications you are taking before starting domperidone, as drug interactions are possible.
Conclusion
Domperidone is mainly used for its antiemetic and prokinetic properties to treat nausea, vomiting, and gastroparesis. While sometimes used off-label for lactation, this is approached with caution due to potential risks, particularly to heart health. Understanding domperidone's uses, how it works, and its safety profile is crucial for its appropriate use under medical guidance.
