A fixed-dose combination (FDC) of a prokinetic agent (Domperidone) and a proton pump inhibitor (Rabeprazole). Domperidone enhances upper gastrointestinal motility and acts as an antiemetic by peripheral dopamine D2 receptor antagonism. Rabeprazole provides potent and long-lasting inhibition of gastric acid secretion by irreversibly blocking the H+/K+ ATPase enzyme system (proton pump) of the gastric parietal cell. This combination is primarily used for the symptomatic treatment of conditions where gastroesophageal reflux is associated with delayed gastric emptying and nausea/vomiting.
Adult: One tablet (Domperidone 30mg + Rabeprazole 20mg) once daily, preferably 15-30 minutes before breakfast. For severe GERD, the dose can be increased to twice daily (morning and evening before meals) as per physician's advice, but the total daily dose of Domperidone should not exceed 30mg.
Note: Swallow the tablet whole with a glass of water. Do NOT crush, chew, or break the tablet as it is enteric-coated (Rabeprazole component). To be taken at least 15-30 minutes before a meal, typically breakfast. If taking twice daily, take before morning and evening meals.
Domperidone acts as a selective peripheral dopamine D2 and D3 receptor antagonist. It blocks dopamine receptors in the chemoreceptor trigger zone (CTZ) and the gastric wall. Blockade in the CTZ produces an antiemetic effect. Blockade in the gastric wall enhances gastroduodenal peristalsis and coordination, increases lower esophageal sphincter pressure, and accelerates gastric emptying, without significant central nervous system effects due to poor blood-brain barrier penetration. Rabeprazole is a prodrug that accumulates in the acidic secretory canaliculi of parietal cells, where it is activated to a sulfenamide. This active form covalently binds to cysteine residues on the H+/K+ ATPase (proton pump), irreversibly inhibiting the final step of gastric acid secretion.
Pregnancy: Rabeprazole: US FDA Pregnancy Category B. Animal studies show no risk, but no adequate human studies. Use only if clearly needed. Domperidone: Not assigned a formal FDA category. Crosses the placenta. Data on use in pregnancy is limited. Should be avoided, especially in the first trimester, unless the potential benefit justifies the potential risk to the fetus.
Driving: Domperidone may rarely cause dizziness, drowsiness, or visual disturbances. Patients should be cautioned about operating machinery or driving until they are sure they are not affected.
| Ketoconazole, Itraconazole, Posaconazole, Voriconazole | Potent CYP3A4 inhibitors. Significantly increase Domperidone plasma levels, raising the risk of QT prolongation and cardiac arrhythmias. CONTRAINDICATED. | High |
| Clarithromycin, Erythromycin | CYP3A4 inhibitors and also prolong QT interval. Increase Domperidone levels and additive QT prolongation risk. CONTRAINDICATED or use with extreme caution. | High |
| Amiodarone, Dronedarone, Quinidine, Sotalol, Procainamide | Drugs that prolong QT interval. Additive risk of serious ventricular arrhythmias with Domperidone. CONTRAINDICATED. | High |
| Atazanavir, Ritonavir | CYP3A4 inhibitors. Increase Domperidone levels. Avoid combination. | High |
| Warfarin | Rabeprazole may potentially alter INR. Monitor INR closely when starting or stopping Rabeprazole. | Moderate |
| Digoxin | Rabeprazole increases gastric pH, which may slightly increase the bioavailability of digoxin. Monitor digoxin levels. | Low |
| Methotrexate | PPIs like Rabeprazole may decrease renal clearance of methotrexate, leading to increased toxicity. Use with caution, especially with high-dose methotrexate. | Moderate |
| Clopidogrel | Rabeprazole, a CYP2C19 inhibitor, may reduce the antiplatelet effect of clopidogrel (a prodrug activated by CYP2C19). Consider using a PPI with less CYP2C19 inhibition (like pantoprazole) if combination is necessary. | Moderate |
| Fluconazole | Moderate CYP3A4/CYP2C19 inhibitor. May increase levels of both drugs. Use with caution and monitor for domperidone side effects. | Moderate |
| Phenytoin, Phenobarbital | CYP inducers. May decrease Rabeprazole levels, reducing efficacy. | Moderate |
| Antacids | Do not take simultaneously. Administer antacids at least 2 hours before or after this combination, as they can interfere with the absorption of both drugs. | Low |