II. Indications

  1. Peptic Ulcer Disease
  2. Gastroesophageal Reflux
  3. Erosive Esophagitis
  4. Zollinger-Ellison Syndrome

III. Contraindications

  1. Hypersensitivity to Proton Pump Inhibitors
  2. Use with caution in severe liver disease

IV. Medications

  1. Omeprazole (Prilosec)
    1. Generic in 2002, OTC
    2. Capsules may be opened and sprinkled on apple sauce
    3. Suspension may be given via Nasogastric Tube or G-Tube
    4. Take at least 30 minutes prior to a meal
  2. Omeprazole with Bicarbonate (Zegerid)
    1. Generic and OTC
    2. May offer benefit in the first week of use, until Omeprazole has reached full effect
    3. Capsules contain 1100 mg Sodium Bicarbonate (300 mg Sodium)
    4. Powders contain 1680 mg Sodium Bicarbonate (460 mg Sodium)
    5. Take on an empty Stomach at least one hour before meals
    6. Capsules must be taken intact with meals
    7. Suspension may be given via Nasogastric Tube

V. Dosing: Adults

  1. See Helicobacter Pylori Treatment
  2. Background
    1. Take 30 to 60 minutes prior to a meal
  3. Duodenal Ulcer or erosive Esophagitis
    1. Take 20 mg orally daily
  4. Gastroesophageal Reflux
    1. Take 20 mg orally daily
  5. Gastric Ulcer
    1. Take 40 mg orally daily
  6. Zollinger Ellison Syndrome
    1. Take 60 mg orally daily

VI. Dosing: Children

  1. Indicated in GERD, erosive Esophagitis, and off-label use for Peptic Ulcers
  2. Background
    1. May sprinkle opened capsule onto applesauce or acidic liquid
  3. Infants
    1. Give 0.7 mg/kg orally daily
  4. Weight 5-10 kg (and age >1 year old)
    1. Give 5 mg orally daily
  5. Weight 10-20 kg
    1. Give 10 mg orally daily
  6. Weight >20 kg
    1. Give 20 mg orally daily
  7. References
    1. Baird (2015) Am Fam Physician 92(8): 705-14 [PubMed]

VII. Pharmacokinetics

  1. All PPIs have short plasma half life of 1-2 hours
  2. Effect is delayed 5-7 days until proton pumps are fully blocked
  3. Metabolized by CYP2C19 and CYP3A4
  4. Inhibits CYP2C19
  5. Induces CYP1A2

VIII. Mechanism

IX. Adverse Effects:

X. Precautions

XI. Safety

  1. Pregnancy Category C (other PPIs are category B)
  2. Unknown safety in Lactation

XII. Efficacy

XIII. Drug Interactions

  1. See Proton Pump Inhibitor
  2. Voriconazole
    1. Doubles the serum levels of Omeprazole
  3. Drug level increases specific to Omeprazole
    1. Carbamazepine (Tegretol)
    2. Diazepam (Valium)
    3. Phenytoin (Dilantin)
    4. Warfarin (Coumadin)
    5. Methotrexate
  4. Clopidogrel (Plavix)
    1. Omeprazole lowers Clopidogrel efficacy
    2. Increased major coronary events occurred within one year of PTCA
      1. Attributed to Omeprazole's interaction with Clopidogrel
      2. Gaglia (2010) Am J Cardiol 105(6): 833-8 [PubMed]
    3. Pantoprazole (Protonix) does not lower Clopidogrel efficacy
      1. Juurlink (2009) CMAJ 180(7): 713-8 [PubMed]
    4. Avoid Omeprazole following PTCA and coronary stenting
      1. Consider H2 Blocker or Pantoprazole instead
    5. As of 2015, no consistent Drug Interaction between Proton Pump Inhibitors and Clopidogrel
      1. Melloni (2015) Circ Cardiovasc Qual Outcomes 8(1): 47-55 +PMID: 25587094 [PubMed]

XIV. Resources

Images: Related links to external sites (from Bing)

Related Studies

Cost: Medications

omeprazole (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
OMEPRAZOLE DR 10 MG CAPSULE Generic $0.09 each
OMEPRAZOLE DR 20 MG CAPSULE Generic $0.03 each
OMEPRAZOLE DR 20 MG ODT Generic OTC $0.41 each
OMEPRAZOLE DR 20 MG TABLET Generic OTC $0.44 each
OMEPRAZOLE DR 40 MG CAPSULE Generic $0.06 each
OMEPRAZOLE MAG DR 20 MG CAP Generic OTC $0.34 each
OMEPRAZOLE MAG DR 20 MG TABLET Generic OTC $0.49 each
OMEPRAZOLE MAG DR 20.6 MG CAP Generic OTC $0.32 each
OMEPRAZOLE-BICARB 20-1,100 CAP Generic $1.11 each
OMEPRAZOLE-BICARB 40-1,100 CAP Generic $0.89 each
OMEPRAZOLE-BICARB 40-1,680 PKT Generic $13.18 each
prilosec (on 1/1/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
PRILOSEC DR 10 MG SUSPENSION $13.19 each
PRILOSEC DR 2.5 MG SUSPENSION $13.29 each

Ontology: Omeprazole (C0028978)

Definition (MSH) A 4-methoxy-3,5-dimethylpyridyl, 5-methoxybenzimidazole derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits an H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS.
Definition (NCI) A benzimidazole with selective and irreversible proton pump inhibition activity. Omeprazole forms a stable disulfide bond with the sulfhydryl group of the hydrogen-potassium (H+ - K+) ATPase found on the secretory surface of parietal cells, thereby inhibiting the final transport of hydrogen ions (via exchange with potassium ions) into the gastric lumen and suppressing gastric acid secretion. This agent exhibits no anticholinergic activities and does not antagonize histamine H2 receptors.
Definition (NCI_NCI-GLOSS) A drug that inhibits gastric acid secretion.
Definition (CSP) substituted benzimidazole used as a gastric acid secretion inhibitor.
Definition (PDQ) A benzimidazole with selective and irreversible proton pump inhibition activity. Omeprazole forms a stable disulfide bond with the sulfhydryl group of the hydrogen-potassium (H+ - K+) ATPase found on the secretory surface of parietal cells, thereby inhibiting the final transport of hydrogen ions (via exchange with potassium ions) into the gastric lumen and suppressing gastric acid secretion. This agent exhibits no anticholinergic properties and does not antagonize histamine H2 receptors. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=42309&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=42309&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C716" NCI Thesaurus)
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D009853
SnomedCT 25673006, 387137007
LNC LP18586-5, MTHU004701
English Omeprazole, 1H-Benzimidazole, 5-methoxy-2-(((4-methoxy-3,5-dimethyl-2-pyridinyl)methyl)sulfinyl)-, OMEP, 5-Methoxy-2-(((4-methoxy-3,5-dimethyl-2-pyridinyl)methyl)sulfinyl)-1H-benzimidazole, omeprazole, omeprazole (medication), OMEPRAZOLE, Omeprazole [Chemical/Ingredient], omeprazole product, Omeprazole (product), Omeprazole (substance)
Swedish Omeprazol
Czech omeprazol
Finnish Omepratsoli
Russian OMEPRAZOL, ОМЕПРАЗОЛ
Croatian OMEPRAZOL
Polish Omeprazol
Japanese オメプラゾール, オメプラール
Spanish omeprazol (producto), omeprazol (sustancia), omeprazol, Omeprazol
French Oméprazole
German Omeprazol
Italian Omeprazolo
Portuguese Omeprazol

Ontology: Prilosec (C0700777)

Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D009853
German Prilosec
English prilosec, PriLOSEC, Prilosec