Mechanism of action-

Hydrochloric acid (HCl) secretion into the gastric lumen is a process regulated mainly by the H(+)/K(+)-ATPase of the proton pump, expressed in high quantities by the parietal cells of the stomach. ATPase is an enzyme on the parietal cell membrane that facilitates hydrogen and potassium exchange through the cell, which normally results in the extrusion of potassium and formation of HCl (gastric acid). Specifically, pantoprazole binds to the sulfhydryl group of H+, K+-ATPase, which is an enzyme implicated in accelerating the final step in the acid secretion pathway. The enzyme is inactivated, inhibiting gastric acid secretion. The inhibition of gastric acid secretion is stronger with proton pump inhibitors such as pantoprazole and lasts longer than with the H(2) antagonists.

Pharmacokinetics-

The apparent volume of distribution of pantoprazole is approximately 11.0-23.6 L and volume of distribution is approximately 98%. Pantoprazole is heavily metabolized in the liver by the cytochrome P450 (CYP) system. After hepatic metabolism, almost 80% of an oral or intravenous dose is excreted as metabolites in urine; the remainder is found in feces and originates from biliary secretion and the half-life is about 1 hour.

Common side effects of injection include:

• Diarrhea
• Flatulence
• Headache
• Nausea
• Stomach pain
• Vomiting
• Dizziness

Do not use this injection in the following conditions:

• An autoimmune disease.
• Systemic lupus erythematosus.
• A type of kidney inflammation called interstitial nephritis.
• Low amount of magnesium in the blood.
• Inadequate vitamin B12.
• Diarrhea from an infection with Clostridium difficile bacteria.

Following drugs may interact with Pantoprazole:

• Ampicillin 
• Warfarin 
• Digoxin 
• Diuretics
• Antifungals such as ketoconazole, itraconazole 
• Iron supplements
• Methotrexate
• Delavirdine