Pantoprazole is a proton pump inhibitor (PPI) that suppresses gastric acid secretion by specifically inhibiting the H+/K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. The 80mg strength is a high-dose formulation primarily used for severe acid-related disorders, including Zollinger-Ellison Syndrome and severe erosive esophagitis, where standard doses are insufficient. It is a substituted benzimidazole sulfoxide.
Adult: Zollinger-Ellison Syndrome: Initial dose 80 mg twice daily. Adjust based on acid output; doses up to 240 mg/day have been used. Severe Erosive Esophagitis: 80 mg once daily for up to 8 weeks. For other conditions, 40mg is standard; 80mg is used under specialist guidance.
Note: Take tablet whole with water, at least 1 hour before a meal (preferably breakfast). Do not crush, chew, or split the tablet. For patients with difficulty swallowing, the tablet can be dispersed in a small amount of water or apple juice, stirred, and consumed immediately (within 30 minutes). Do not use carbonated liquids.
Pantoprazole is a prodrug that accumulates in the acidic environment of the parietal cell canaliculus. It is activated to a sulfenamide derivative, which forms covalent disulfide bonds with cysteine residues (Cys813 and Cys822) on the alpha subunit of the H+/K+ ATPase (proton pump). This irreversible inhibition blocks the final step of gastric acid secretion, leading to profound and long-lasting suppression of both basal and stimulated acid production.
Pregnancy: Category B: Animal studies have shown no risk, but adequate and well-controlled studies in pregnant women are lacking. Use only if clearly needed. PPIs are not considered major teratogens, but the 80mg high dose should be used with extreme caution.
Driving: Pantoprazole is unlikely to impair the ability to drive or use machines. However, patients experiencing dizziness or visual disturbances should exercise caution.
| Atazanavir, Nelfinavir (HIV Protease Inhibitors) | Pantoprazole reduces gastric acidity, significantly decreasing the absorption and plasma concentration of these drugs, leading to loss of virologic response. | Major |
| Rilpivirine | Concomitant use is contraindicated. Reduced absorption leads to antiviral failure. | Major |
| Ketoconazole, Itraconazole, Posaconazole | Reduced gastric acidity decreases absorption of these weak-base antifungals, potentially reducing efficacy. | Moderate |
| Methotrexate | PPIs may reduce renal clearance of methotrexate, leading to increased methotrexate levels and toxicity, especially with high-dose methotrexate. | Moderate |
| Warfarin | Potential for increased INR and risk of bleeding due to possible interaction via CYP2C19. Close monitoring of INR is required. | Moderate |
| Clopidogrel | Pantoprazole (a moderate CYP2C19 inhibitor) may reduce the antiplatelet effect of clopidogrel (a prodrug activated by CYP2C19), potentially increasing cardiovascular risk. This interaction is controversial but should be considered. | Moderate |
| Digoxin | Increased gastric pH may slightly increase the bioavailability of digoxin. | Minor |
| Iron Salts (Ferrous Sulfate) | Reduced gastric acidity decreases conversion of ferric to ferrous iron, impairing absorption. Separate administration by 2-4 hours. | Moderate |
Same composition (Pantoprazole (80mg)), different brands: