Omeprazole

Mechanism :

Omeprazole belongs to a class of antisecretory compounds, that do not exhibit anticholinergic or H2 histamine antagonistic properties, but that suppress gastric acid secretion by specific inhibition of the H+/K+ ATPase enzyme system at the secretory surface of the gastric parietal cell.

Indication :

• Gastro-esophageal reflux
• Esophageal gastric varices bleeding prophylaxis, erosive esophagitis
• Acid peptic disease resistant to ranitidine
• Helicobacter pylori eradication
• Fat malabsorption despite optimal use of replacement in cystic fibrosis

Contraindications :

Contraindicated in patients with known hypersensitivity to any component of the formulation. Treatment with omeprazole may mask the symptoms of other gastric disease. Caution should be exercised in patients with hepatic impairment.

Dosing :

Adverse Effect :

Headache, dizziness, rash, urticaria, pruritus, diarrhea, gastric glandular cysts (on prolonged treatment), cough, upper respiratory infection, irreversible visual impairment in critically ill patients who have received high doses of IV omeprazole. Others: blood dyscrasias, hepatic impairment, hypersensitivity reaction, anaphylaxis, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, pancreatitis, interstitial nephritis, rhabdomyolysis, fractures, hyponatremia, hypomagnesemia (long-term use), atrophic gastritis (long-term use), clostridium difficile associated diarrhea, headache, nausea/vomiting, diarrhea, thrombophlebitis (IV use), abdominal pain, fever, rash, dizziness,

flatulence, arthralgia.

Interaction :

Diazepam, Warfarin and Phenytoin: Omeprazole can prolong the elimination of diazepam, warfarin and phenytoin, drugs that are metabolized by oxidation in the liver. There have been reports of increased INR and prothrombin time in patients receiving proton pump inhibitors, including omeprazole, and warfarin concomitantly.
Ampicillin Esters, Iron Salts: omeprazole may interfere with absorption of drugs where gastric pH is an important determinant of their bioavailability.
Tacrolimus: Concomitant administration of omeprazole and tacrolimus may increase the serum levels of tacrolimus.
Atazanavir: Concomitant administration of omeprazole has been reported to reduce the plasma levels of atazanavir.

Renal Dose :

Hepatic Dose :