Esomeprazole is the S-isomer of omeprazole, a proton pump inhibitor (PPI) that suppresses gastric acid secretion by specific inhibition of the H+/K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. It is a first-line therapy for acid-related disorders in India, valued for its efficacy, safety, and predictable pharmacokinetics.
Adult: GERD (Healing): 40mg once daily for 4-8 weeks. GERD (Maintenance): 20mg once daily. Peptic Ulcer: 20mg-40mg once daily for 4-8 weeks. H. pylori Eradication: 20mg twice daily with antibiotics. NSAID Ulcer Prevention: 20mg-40mg once daily.
Note: Swallow the tablet/capsule whole with a glass of water, at least 1 hour before a meal (preferably breakfast). DO NOT crush, chew, or break the enteric-coated pellet formulation. For patients with swallowing difficulties, capsules can be opened and the pellets mixed in 1 tablespoon of cool, soft applesauce, swallowed immediately without chewing.
Esomeprazole is a prodrug. It is absorbed in the small intestine, enters the bloodstream, and is concentrated in the acidic secretory canaliculi of the parietal cell. In this highly acidic environment, it is protonated and rearranges into its active form, sulfenamide. This active metabolite forms covalent disulfide bonds with cysteine residues (specifically Cys813 and Cys892) on the luminal surface of the H+/K+ ATPase (proton pump), irreversibly inhibiting the enzyme's ability to secrete hydrogen ions (H+) into the gastric lumen.
Pregnancy: Pregnancy Category B (US FDA). Animal studies have shown no direct fetal harm. Limited human data. Should be used during pregnancy only if clearly needed, after consulting a physician. Consider risks vs. benefits.
Driving: Esomeprazole is unlikely to affect the ability to drive or use machines. However, if dizziness or visual disturbances occur, patients should avoid these activities.
| Clopidogrel | Esomeprazole (a CYP2C19 inhibitor) may reduce the antiplatelet effect of clopidogrel (a prodrug activated by CYP2C19), potentially increasing cardiovascular risk. Avoid combination if possible. | Major |
| Ketoconazole, Itraconazole, Posaconazole | Reduced absorption of these antifungals due to increased gastric pH. Administer antifungals with an acidic beverage or separate dosing. | Moderate |
| Atazanavir, Rilpivirine | Significantly reduces absorption of these HIV protease/NNRTI inhibitors, leading to therapeutic failure. Contraindicated. | Major |
| Methotrexate | May increase methotrexate levels and toxicity (especially with high-dose methotrexate) by competing for renal tubular secretion. | Major |
| Diazepam, Phenytoin | May increase levels of these drugs (metabolized by CYP2C19). Monitor for toxicity. | Moderate |
| Cilostazol | Increases cilostazol active metabolite levels; consider dose reduction of cilostazol. | Moderate |
| Digoxin | May slightly increase digoxin bioavailability. Monitor digoxin levels. | Minor |
| Warfarin | Potential for increased INR and bleeding risk due to CYP2C19/2C9 inhibition. Monitor INR closely. | Moderate |
| Tacrolimus | May increase tacrolimus blood concentration. Monitor levels. | Moderate |