section name header

Pronunciation

o-MEP-ra-zole

Classifications

Therapeutic Classification: antiulcer agents

Pharmacologic Classification: proton pump inhibitors

Indications

BEERS REMS


OTC

Action

  • Binds to an enzyme on gastric parietal cells in the presence of acidic gastric pH, preventing the final transport of hydrogen ions into the gastric lumen.
Therapeutic effects:
  • Diminished accumulation of acid in the gastric lumen with lessened gastroesophageal reflux.
  • Healing of duodenal ulcers.

Pharmacokinetics

Absorption: Rapidly absorbed following oral administration; immediate release formulation contains bicarbonate to prevent acid degradation.

Distribution: Good distribution into gastric parietal cells.

Protein Binding: 95%.

Metabolism/Excretion: Mostly metabolized by the liver via the CYP2C19 isoenzyme, and to a lesser extent by the CYP3A4 isoenzyme; the CYP2C19 isoenzyme exhibits genetic polymorphism (15–20% of Asian patients and 3–5% of Caucasian and Black patients may be poor metabolizers and may have significantly omeprazole concentrations and an risk of adverse effects); inactive metabolites are excreted in urine (77%) and feces.

Half-Life: 0.5–1 hr ( in liver disease to 3 hr).

Time/Action Profile

(antisecretory effects)

ROUTEONSETPEAKDURATION
PO-delayed releasewithin 1 hrwithin 2 hr72–96 hr





Contraind./Precautions

Contraindicated in:

Use Cautiously in:

Adv. Reactions/Side Effects

CV: chest pain

Derm: ACUTE GENERALIZED EXANTHEMATOUS PUSTULOSIS, cutaneous lupus erythematosus, DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), itching, rash, STEVENS-JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS

F and E: hypocalcemia (especially if treatment duration 3 mo), hypokalemia (especially if treatment duration 3 mo), hypomagnesemia (especially if treatment duration 3 mo)

GI: abdominal pain, CLOSTRIDIOIDES DIFFICILE-ASSOCIATED DIARRHEA (CDAD), constipation, diarrhea, flatulence, fundic gland polyps, nausea, vomiting

GU: acute tubulointerstitial nephritis

MS: bone fracture

Neuro: dizziness, drowsiness, fatigue, headache, weakness

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS, ANGIOEDEMA, OR TUBULOINTERSTITIAL NEPHRITIS), systemic lupus erythematosus, vitamin B12 deficiency

Interactions

Drug-drug:

Drug-Natural Products:

Route/Dosage

Availability

(Generic available)

Assessment

Lab Test Considerations:

Implementation

Patient/Family Teaching

Evaluation/Desired Outcomes

US Brand Names

PriLOSEC, PriLOSEC OTC

Canadian Brand Names

Losec

Pill Image

omeprazole_rx_195-8644.jpg