PRILOSEC is a proton pump inhibitor indicated for:
• Treatment in adults of duodenal ulcer and gastric ulcer
• Treatment in adults and children of gastroesophageal reflux disease (GERD) and maintenance of healing of erosive esophagitis. The safety and effectiveness of PRILOSEC in pediatric patients <1 year of age have not been established.

Adults: Most common adverse reactions in adults (incidence ≥ 2%) are
• Headache, abdominal pain, nausea, diarrhea, vomiting, and flatulence
Pediatric patients (1 to 16 years of age):
Safety profile similar to that in adults, except that respiratory system events and fever were the most frequently reported reactions in pediatric studies

• Atazanavir and nelfinavir: PRILOSEC reduces plasma levels of atazanavir and nelfinavir. Concomitant use is not recommended
• Saquinavir: PRILOSEC increases plasma levels of saquinavir. Monitor for toxicity and consider dose reduction of saquinavir
• May interfere with drugs for which gastric pH affects bioavailability (e.g., ketoconazole, iron salts, ampicillin esters, and digoxin). Patients treated with PRILOSEC and digoxin may need to be monitored for increases in digoxin toxicity
• Co-administration of clopidogrel with 80 mg omeprazole may reduce the pharmacological activity of clopidogrel if given concomitantly or if given 12 hours apart
• Cilostazol: PRILOSEC increases systemic exposure of cilostazol and one of its active metabolites. Consider dose reduction of cilostazol.
• Drugs metabolized by cytochrome P450 (e.g., diazepam, warfarin, phenytoin, cyclosporine, disulfiram, benzodiazepines): PRILOSEC can prolong their elimination. Monitor and determine need for dose
adjustments
• Patients treated with proton pump inhibitors and warfarin may need to be monitored for increases in INR and prothrombin time
• Combined inhibitor of CYP 2C19 and 3A4 (e.g. voriconazole) may raise omeprazole levels
• Tacrolimus: PRILOSEC may increase serum levels of tacrolimus
• Methotrexate: PRILOSEC may increase serum levels of methotrexate

• Symptomatic response does not preclude the presence of gastric malignancy
• Atrophic gastritis: has been noted with long-term therapy
• PPI therapy may be associated with increased risk of Clostridium difficile associated diarrhea.
• Bone Fracture: Long-term and multiple daily dose PPI therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist or spine.
• Diminished anti-platelet activity of clopidogrel due to impaired CYP2C19 function by 80 mg omeprazole
• Hypomagnesemia has been reported rarely with prolonged treatment with PPIs
• Avoid concomitant use of PRILOSEC with St John’s Wort or rifampin due to the potential reduction in omeprazole concentrations
• Interactions with diagnostic investigations for Neuroendocrine Tumors: Increases in intragastric pH may result in hypergastrinemia and enterochromaffin-like cell hyperplasia and increased Choromogranin A levels which may interfere with diagnostic investigations for neuroendocrine tumors.