Overview
Pantoprazole is a proton pump inhibitor (PPI) that suppresses gastric acid secretion by irreversibly inhibiting the H+/K+ ATPase enzyme system in gastric parietal cells. It is used for the treatment of gastroesophageal reflux disease (GERD), erosive esophagitis, and pathological hypersecretory conditions. Clinical effects are dose-dependent with maximal acid suppression achieved within 2-3 hours after administration.
Mechanism of Action
Pantoprazole is a substituted benzimidazole that selectively and irreversibly inhibits the H+/K+ ATPase enzyme system (proton pump) in gastric parietal cells. This inhibition blocks the final step of acid production, leading to prolonged suppression of both basal and stimulated gastric acid secretion regardless of the stimulus.
Indications
- Short-term treatment of erosive esophagitis associated with GERD
- Maintenance of healing of erosive esophagitis
- Pathological hypersecretory conditions including Zollinger-Ellison syndrome
Common Doses
- 20 mg
- 40 mg
Dosage
Typical adult dosage is 40 mg once daily for 8 weeks for healing of erosive esophagitis, followed by 40 mg once daily for maintenance therapy. For pathological hypersecretory conditions, initial dose is 40 mg twice daily, adjusted based on acid output measurements.
Contraindications
- Known hypersensitivity to pantoprazole, any component of the formulation, or substituted benzimidazoles
- Concomitant use with rilpivirine-containing products
Side Effects
- Headache
- Diarrhea
- Nausea
- Abdominal pain
- Flatulence
- Dizziness
- Arthralgia
- Increased liver enzymes
- Rash
- Acute tubulointerstitial nephritis
- Clostridium difficile-associated diarrhea
- Hypomagnesemia
- Vitamin B12 deficiency
Interactions
- Rilpivirine: Contraindicated (reduced antiretroviral efficacy)
- Atazanavir: Reduced absorption (consult prescribing information)
- Warfarin: Increased INR/prothrombin time (monitor closely)
- Methotrexate: Possible increased methotrexate levels (consider temporary withdrawal)
- Drugs dependent on gastric pH: Reduced absorption of iron salts, ketoconazole, itraconazole, erlotinib, dasatinib, nilotinib, mycophenolate mofetil
- Clopidogrel: No clinically significant interaction at approved doses
- False positive urine THC tests
- Interference with chromogranin A testing for neuroendocrine tumors
Counseling Points
- Take tablet whole, do not crush or chew
- Take before meals, preferably in the morning
- May take with or without food
- Report persistent diarrhea, new joint pain, or skin rash
- Long-term users should discuss bone health and magnesium/vitamin B12 monitoring with healthcare provider
- Do not stop taking abruptly without medical advice