Drug Name

Prilosec (generic name: omeprazole) is a proton pump inhibitor used primarily for reducing stomach acid.

Therapeutic Uses

Prilosec is prescribed for the treatment of gastrointestinal conditions such as gastroesophageal reflux disease (GERD), duodenal ulcers, and erosive esophagitis. It also serves as a long-term treatment for conditions like Zollinger-Ellison syndrome.

Dosage Forms

Prilosec is available in various forms, including delayed-release capsules, oral suspension, and over-the-counter tablets. The dosage typically ranges from 10 mg to 40 mg based on the condition treated.

Mechanism of Action

Omeprazole inhibits the H+/K+ ATPase enzyme in the stomach lining’s parietal cells, effectively reducing gastric acid production at the final step.

Pharmacokinetics

Following oral administration, peak plasma concentrations of omeprazole are usually achieved within 0.5 to 3.5 hours. The drug is metabolized by the liver, primarily by CYP2C19 and CYP3A4 enzymes, and excreted via urine and feces.

Food Interaction

Taking Prilosec before meals enhances its effectiveness. Administering it on an empty stomach improves absorption but taking it with food can reduce its bioavailability by approximately 35%.

Initial Dosing

For initial treatment of GERD, the standard dose is 20 mg once daily for 4 to 8 weeks. For duodenal ulcers, the usual dose is 20 mg for 2 to 8 weeks.

Maintenance Dosing

For long-term management, a reduced dose such as 10 to 20 mg may be prescribed once daily. For Zollinger-Ellison syndrome, dosing may be individualized based on gastric acid output monitoring.

Administration Instructions

Prilosec capsules should be swallowed whole with water, not chewed or crushed. For patients unable to swallow capsules, oral suspension or dispersible tablets mixed with apple juice or applesauce may be used.

Storage Guidelines

Store Prilosec at room temperature, away from moisture and heat. Keep it in its original container and out of reach of children.

Monitoring Requirements

Patients should undergo periodic monitoring of liver enzyme levels and renal function during long-term therapy. Monitoring magnesium levels is also recommended, as hypomagnesemia has been reported with prolonged use.

Enzyme Inhibition

Omeprazole can inhibit the enzyme CYP2C19, which may affect the metabolism of drugs like diazepam, warfarin, and phenytoin. Close monitoring is essential when co-administered with these medications.

Contraindications

Prilosec is contraindicated in patients with known hypersensitivity to omeprazole or any other proton pump inhibitors.

Drug Interactions

Concurrent use of Prilosec with clopidogrel can reduce the anti-platelet effect of clopidogrel. Prilosec may also decrease the absorption of drugs dependent on gastric pH, such as ketoconazole and atazanavir.

Pregnancy Category

Prilosec is classified as a pregnancy category C drug. Clinical consideration is required to determine the risk versus benefit for pregnant patients.

Breastfeeding Consideration

Omeprazole is excreted in human milk. Caution is advised when Prilosec is administered to a breastfeeding woman.

Adverse Reactions

Common adverse effects include headache, abdominal pain, nausea, diarrhea, and flatulence. Rare but serious side effects include Clostridium difficile infection, hypomagnesemia, and bone fracture.

Patient Counseling

Advise patients to take Prilosec as directed, typically 30 to 60 minutes before a meal. Inform patients to report any persisting symptoms or adverse effects immediately.

Off-Label Uses

Prilosec has been utilized off-label for conditions such as Helicobacter pylori eradication, Barrett’s esophagus, and laryngopharyngeal reflux.

Generic Availability

Omeprazole, the generic form of Prilosec, is widely available and offers a cost-effective alternative to the brand name product without compromising efficacy.

Cost Considerations

While brand name Prilosec may be more expensive, insurance plans often cover its cost, and patient assistance programs may also be available to reduce financial burden.