Omeprazole: Difference between revisions

{{Use dmy dates|date=OctoberJanuary 20212024}}

| tradename = Losec, Prilosec, Zegerid, others<ref name=AHFS2015/><ref name="Drugs.com international" />

| ATC_supplemental = {{ATC|A02|BC51}}

| legal_CA = <!-- OTC, Rx-only, Schedule I, II, III, IV, V, VI, VII, VIII -->

| bioavailability= 35–76%<ref>{{cite web | title=Prilosec- omeprazole magnesium capsule, delayed release Prilosec- omeprazole magnesium granule, delayed release | website=DailyMed | date=22 December 2016 | url=https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a1b077e6-b070-43f2-a98e-380cc635419d | access-date=15 February 2020 | archive-date=27 December 2019 | archive-url=https://web.archive.org/web/20191227184048/https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a1b077e6-b070-43f2-a98e-380cc635419d | url-status=live }}</ref><ref>{{cite journal | vauthors = Vaz-da-Silva M, Loureiro AI, Nunes T, Maia J, Tavares S, Falcão A, Silveira P, Almeida L, Soares-da-Silva P | display-authors = 6 | title = Bioavailability and bioequivalence of two enteric-coated formulations of omeprazole in fasting and fed conditions | journal = Clinical Drug Investigation | volume = 25 | issue = 6 | pages = 391–399 | year = 2005 | pmid = 17532679 | doi = 10.2165/00044011-200525060-00004 | url = http://www.medscape.com/viewarticle/508018 | url-status = live | access-date = 21 October 2018 | s2cid = 22082780 | archive-url = https://web.archive.org/web/20130313204630/http://www.medscape.com/viewarticle/508018 | archive-date = 13 March 2013 }}</ref>

| metabolism = [[Liver|Hepatic]] ([[CYP2C19]], [[CYP3A4]])

'''Omeprazole''', sold under the brand names '''Prilosec''' and '''Losec''', among others, is a medication used in the treatment of [[gastroesophageal reflux disease]] (GERD), [[peptic ulcer disease]], and [[Zollinger–Ellison syndrome]].<ref name="AHFS2015">{{cite web |title=Omeprazole |url=https://www.drugs.com/monograph/omeprazole.html |publisher=The American Society of Health-System Pharmacists |access-date=21 October 2018 |archive-date=19 February 2011 |archive-url=https://web.archive.org/web/20110219135631/http://www.drugs.com/monograph/omeprazole.html |url-status=live }}</ref> It is also used to prevent [[upper gastrointestinal bleeding]] in people who are at high risk.<ref name=AHFS2015/> Omeprazole is a [[proton-pump inhibitor]] (PPI) and its effectiveness is similar to that of other PPIs.<ref name=TI2016>{{cite web|title=[99] Comparative effectiveness of proton pump inhibitors {{!}} Therapeutics Initiative|url=http://www.ti.ubc.ca/2016/06/28/99-comparative-effectiveness-proton-pump-inhibitors/|access-date=14 July 2016|date=28 June 2016|archive-date=30 October 2020|archive-url=https://web.archive.org/web/20201030063031/https://www.ti.ubc.ca/2016/06/28/99-comparative-effectiveness-proton-pump-inhibitors/|url-status=live}}</ref> It can be taken by mouth or by [[intravenous|injection into a vein]].<ref name=AHFS2015/><ref name=UK2016>{{cite web |title=Omeprazole 40 mg Powder for Solution for Infusion |url=https://www.medicines.org.uk/emc/medicine/25259 |website=EMC |access-date=21 October 2018 |date=10 February 2016 |url-status=live |archive-url=https://web.archive.org/web/20160407193540/https://www.medicines.org.uk/emc/medicine/25259 |archive-date=7 April 2016}}</ref> It is also available in the fixed-dose [[combination medication]] omeprazole/sodium bicarbonate as Zegerid<ref name="Zegerid FDA label">{{cite web | title=Zegerid- omeprazole and sodium bicarbonate powder, for suspension Zegerid- omeprazole and sodium bicarbonate capsule | website=DailyMed | date=4 March 2022 | url=https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cd6868b9-5824-442b-8d65-4db29ecb70a4 | access-date=16 December 2022}}</ref><ref name="Zegerid OTC FDA label">{{cite web | title=Zegerid OTC- omeprazole and sodium bicarbonate capsule, gelatin coated | website=DailyMed | date=5 December 2022 | url=https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5ad1ca2b-3119-b8c2-e053-2a91aa0a2f77 | access-date=16 December 2022}}</ref> and as Konvomep.<ref>{{cite web | title=Konvomep- omeprazole and sodium bicarbonate kit | website=DailyMed | date=30 August 2022 | url=https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=688ed6f1-d78a-4006-a682-57021cb38a3e | access-date=21 January 2023}}</ref>

Common side effects include nausea, vomiting, headaches, abdominal pain, and [[flatulence|increased intestinal gas]].<ref name=AHFS2015/><ref name=Dav2015 /> Serious side effects may include [[Clostridium difficile colitis|''Clostridium difficile'' colitis]], an increased risk of [[pneumonia]], an increased risk of [[bone fractures]], and the potential of masking [[stomach cancer]].<ref name=AHFS2015/> It is unclear ifWhether it is safe for use in [[pregnancy]] is unclear.<ref name=AHFS2015/> It works by blocking the release of [[stomach acid]].<ref name=AHFS2015/>

Omeprazole was patented in 1978, and approved for medical use in 1988.<ref>{{cite web | title=Drug Approval Package: Prilosec (Omeprazole) NDA# 019-810s38s50s5 | website=U.S. [[Food and Drug Administration]] (FDA) | date=30 March 2001 | url=https://www.accessdata.fda.gov/drugsatfda_docs/nda/98/019810s38s50s56.cfm | access-date=5 October 2022 | archive-date=1 April 2021 | archive-url=https://web.archive.org/web/20210401151454/https://www.accessdata.fda.gov/drugsatfda_docs/nda/98/019810s38s50s56.cfm | url-status=live }}</ref><ref>{{cite book | vauthors = Fischer J, Ganellin CR |title=Analogue-based Drug Discovery |date=2006 |publisher=John Wiley & Sons |isbn=9783527607495 |page=445 |url=https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA445 |access-date=29 June 2020 |archive-date=3 August 2020 |archive-url=https://web.archive.org/web/20200803230101/https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA445 |url-status=live }}</ref> It is on the [[WHO Model List of Essential Medicines|World Health Organization's List of Essential Medicines]].<ref name="WHO21st">{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 21st list 2019 | year = 2019 | hdl = 10665/325771 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO | hdl-access=free }}</ref> It is available as a [[generic medication]].<ref name=AHFS2015/> In 20202021, it was the eighth -most commonly prescribed medication in the United States, with more than 5654{{nbsp}}million prescriptions.<ref>{{cite web | title=The Top 300 of 20202021 | url=https://clincalc.com/DrugStats/Top300Drugs.aspx | website=ClinCalc | access-date=14 January 2024 | archive-date=15 January 2024 | archive-url=https://web.archive.org/web/20240115223848/https://clincalc.com/DrugStats/Top300Drugs.aspx | accessurl-datestatus=7 October 2022live }}</ref><ref>{{cite web | title=Omeprazole - Drug Usage Statistics, ClinCalc DrugStats Database | website=ClinCalc | url=https://clincalc.com/DrugStats/Drugs/Omeprazole | access-date=7 October 2022 | archive-date=2814 FebruaryJanuary 20202024 }}</ref> It is also available without a prescription in the United States.<ref>{{cite web |title=Questions and Answers on Prilosec OTC (omeprazole) |url=https://www.fda.gov/about-fda/center-drug-evaluation-and-research-cder/questions-and-answers-prilosec-otc-omeprazole |website=U.S. [[Food and Drug Administration]] (FDA) |access-date=2 March 2020 |date=3 November 2018 |archive-date=28 August 2021 |archive-url=https://web.archive.org/web/20210828195503/https://www.fda.gov/about-fda/center-drug-evaluation-and-research-cder/questions-and-answers-prilosec-otc-omeprazole |url-status=live }}</ref><ref>{{cite web | title=Drug Approval Package: Prilosec (Omeprazole Magnesium) NDA #021229 | website=U.S. [[Food and Drug Administration]] (FDA) | url=https://www.accessdata.fda.gov/drugsatfda_docs/nda/2003/21-229_Prilosec.cfm | access-date=6 October 2022 | archive-date=24 January 2022 | archive-url=https://web.archive.org/web/20220124210732/https://www.accessdata.fda.gov/drugsatfda_docs/nda/2003/21-229_Prilosec.cfm | url-status=live }}</ref>

Peptic ulcers may be treated with omeprazole. TreatmentInfection of awith ''[[Helicobacter pylori]]'' infection can be completedtreated by taking a triple therapy combination of omeprazole, [[amoxicillin]], and [[clarithromycin]] together for 7–14 days.<ref>{{cite journal | vauthors = Fuccio L, Minardi ME, Zagari RM, Grilli D, Magrini N, Bazzoli F | title = Meta-analysis: duration of first-line proton-pump inhibitor based triple therapy for Helicobacter pylori eradication | journal = Annals of Internal Medicine | volume = 147 | issue = 8 | pages = 553–562 | date = October 2007 | pmid = 17938394 | doi = 10.7326/0003-4819-147-8-200710160-00008 | s2cid = 11644009 }}</ref> Amoxicillin may be replaced with [[metronidazole]] in patients who are allergic to penicillin.<ref name="Maastricht_2_Consensus_Report">{{cite journal | vauthors = Malfertheiner P, Megraud F, O'Morain C, Bazzoli F, El-Omar E, Graham D, Hunt R, Rokkas T, Vakil N, Kuipers EJ | display-authors = 6 | title = Current concepts in the management of Helicobacter pylori infection: the Maastricht III Consensus Report | journal = Gut | volume = 56 | issue = 6 | pages = 772–781 | date = June 2007 | pmid = 17170018 | pmc = 1954853 | doi = 10.1136/gut.2006.101634 }}</ref>

Adverse effects occurring in at least 1% of people include:<ref>{{cite journal | vauthors = McTavish D, Buckley MM, Heel RC | title = Omeprazole. An updated review of its pharmacology and therapeutic use in acid-related disorders | journal = Drugs | volume = 42 | issue = 1 | pages = 138–170 | date = July 1991 | pmid = 1718683 | doi = 10.2165/00003495-199142010-00008 }}</ref>{{Failed verification|date=February 2023}}

*Recurrence of ''[[Clostridium difficile colitis|Clostridium difficile]]'' associated diarrhea<ref>{{cite journal | vauthors = Abou Chakra CN, Pepin J, Sirard S, Valiquette L | title = Risk factors for recurrence, complications and mortality in Clostridium difficile infection: a systematic review | journal = PloSPLOS OneONE | volume = 9 | issue = 6 | pages = e98400 | date = 21 June 2014 | pmid = 24897375 | pmc = 4045753 | doi = 10.1371/journal.pone.0098400 | bibcode = 2014PLoSO...998400A | doi-access = free }}</ref>

*[[osteoporosis#Fractures|Osteoporosis-related fractures]]<ref>{{cite journal | vauthors = Yang YX, Lewis JD, Epstein S, Metz DC | title = Long-term proton pump inhibitor therapy and risk of hip fracture | journal = JamaJAMA | volume = 296 | issue = 24 | pages = 2947–2953 | date = December 2006 | pmid = 17190895 | doi = 10.1001/jama.296.24.2947 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Yu EW, Bauer SR, Bain PA, Bauer DC | title = Proton pump inhibitors and risk of fractures: a meta-analysis of 11 international studies | journal = The American Journal of Medicine | volume = 124 | issue = 6 | pages = 519–526 | date = June 2011 | pmid = 21605729 | pmc = 3101476 | doi = 10.1016/j.amjmed.2011.01.007 }}</ref>

Concern has been expressed regarding [[vitamin B12|vitamin B₁₂]]<ref>{{cite journal | vauthors = Neal K, Logan R | title = Potential gastrointestinal effects of long-term acid suppression with proton pump inhibitors | journal = Alimentary Pharmacology & Therapeutics | volume = 15 | issue = 7 | pages = 1085–1086 | date = July 2001 | pmid = 11421886 | doi = 10.1046/j.1365-2036.2001.0994a.x | s2cid = 39455836 | doi-access = free }}</ref> and [[iron]] [[malabsorption]],<ref>{{cite journal | vauthors = Sarzynski E, Puttarajappa C, Xie Y, Grover M, Laird-Fick H | title = Association between proton pump inhibitor use and anemia: a retrospective cohort study | journal = Digestive Diseases and Sciences | volume = 56 | issue = 8 | pages = 2349–2353 | date = August 2011 | pmid = 21318590 | doi = 10.1007/s10620-011-1589-y | s2cid = 33574008 }}</ref> but effects seem to be insignificant, especially when supplement therapy is provided.<ref>{{cite journal | vauthors = McColl KE | title = Effect of proton pump inhibitors on vitamins and iron | journal = The American Journal of Gastroenterology | volume = 104 | issue = Suppl 2 | pages = S5-S9S5–S9 | date = March 2009 | pmid = 19262546 | doi = 10.1038/ajg.2009.45 | s2cid = 31455416 }}</ref>

There is a possible association between long term use and [[dementia]] which requires further study to confirm.<ref>{{cite journal | vauthors = Eusebi LH, Rabitti S, Artesiani ML, Gelli D, Montagnani M, Zagari RM, Bazzoli F | title = Proton pump inhibitors: Risks of long-term use | journal = Journal of Gastroenterology and Hepatology | volume = 32 | issue = 7 | pages = 1295–1302 | date = July 2017 | pmid = 28092694 | doi = 10.1111/jgh.13737 | doi-access = free }}</ref>

A review article in ''[[U.S. Pharmacist]]'' in 2013 states that long-term use of PPIs is associated with [[Hypocalcaemia|decreased calcium absorption]] (causing increased risk of [[osteoporosis]] and [[Bone fracture|fractures]]), [[Magnesium deficiency|decreased magnesium absorption]] (causing [[Electrolyte imbalance|electrolyte disturbances]]), and increased risk of certain infections such as ''[[C. difficile]]'' and [[community-acquired pneumonia]]. They hypothesize that this is due to decreased stomach acid production.<ref>{{Cite cite journal | vauthors = O'Neill LW, Culpepper BL, Galdo JA |title=Long-Term Consequences of Chronic Proton Pump Inhibitor Use | journal = US Pharmacist | date = 2013 | volume = 38 | issue = 12 | pages = 38-4238–42 |url= https://www.uspharmacist.com/article/longterm-consequences-of-chronic-proton-pump-inhibitor-use|access-date=28 December 2020 |archive-date=21 January 2021|archive-url=https://web.archive.org/web/20210121163435/https://www.uspharmacist.com/article/longterm-consequences-of-chronic-proton-pump-inhibitor-use|url-status=live}}</ref>

The safety of using omeprazole has not been established in pregnant or breastfeeding women.<ref name=Dav2015>{{cite book|title=Davis's Drug Guide for Nurses| vauthors = Vallerand AH, Sanoski CA, Deglin JH |publisher=F.A. Davis Company|year=2015|isbn=978-0-8036-4085-6|edition=14th|pages=924–925|oclc=881473728}}</ref> Epidemiological data do not show an increased risk of major birth defects after maternal use of omeprazole during [[pregnancy]].<ref>{{cite journal | vauthors = Pasternak B, Hviid A | title = Use of proton-pump inhibitors in early pregnancy and the risk of birth defects | journal = The New England Journal of Medicine | volume = 363 | issue = 22 | pages = 2114–2123 | date = November 2010 | pmid = 21105793 | doi = 10.1056/NEJMoa1002689 | s2cid = 10954538 | doi-access = free }}</ref>

This interaction is possible because omeprazole is an [[enzyme inhibitor|inhibitor]] of the enzymes [[CYP2C19]] and [[CYP3A4]].<ref>{{cite journal | vauthors = Shirasaka Y, Sager JE, Lutz JD, Davis C, Isoherranen N | title = Inhibition of CYP2C19 and CYP3A4 by omeprazole metabolites and their contribution to drug-drug interactions | journal = Drug Metabolism and Disposition | volume = 41 | issue = 7 | pages = 1414–1424 | date = July 2013 | pmid = 23620487 | pmc = 3684819 | doi = 10.1124/dmd.113.051722 }}</ref> [[Clopidogrel]] is an inactive [[prodrug]] that partially depends on CYP2C19 for conversion to its active form. Inhibition of CYP2C19 may block the activation of clopidogrel, which could reduce its effects.<ref>{{cite journal | vauthors = Lau WC, Gurbel PA | title = The drug-drug interaction between proton pump inhibitors and clopidogrel | journal = CmajCMAJ | volume = 180 | issue = 7 | pages = 699–700 | date = March 2009 | pmid = 19332744 | pmc = 2659824 | doi = 10.1503/cmaj.090251 }}</ref><ref>{{cite journal | vauthors = Norgard NB, Mathews KD, Wall GC | title = Drug-drug interaction between clopidogrel and the proton pump inhibitors | journal = The Annals of Pharmacotherapy | volume = 43 | issue = 7 | pages = 1266–1274 | date = July 2009 | pmid = 19470853 | doi = 10.1345/aph.1M051 | s2cid = 13227312 }}</ref>

Almost all [[benzodiazepines]] are metabolised by the CYP3A4 and [[CYP2D6]] pathways, and inhibition of these enzymes results in a higher [[Area under the curve (pharmacokinetics)|area under the curve]] (''i.e.'', the total effect over time of a given dose). Other examples of drugs dependent on CYP3A4 for their metabolism are [[escitalopram]],<ref>{{EMedicine|article|1879354|Selective Serotonin Reuptake Inhibitors and CYP2D6}}</ref> [[warfarin]],<ref name="pmid12724615">{{cite journal | vauthors = Daly AK, King BP | title = Pharmacogenetics of oral anticoagulants | journal = Pharmacogenetics | volume = 13 | issue = 5 | pages = 247–252 | date = May 2003 | pmid = 12724615 | doi = 10.1097/00008571-200305000-00002 }}</ref> [[oxycodone]], [[tramadol]], and [[oxymorphone]]. The concentrations of these drugs may increase if they are used concomitantly with omeprazole.<ref name=Stedman>{{cite journal | vauthors = Stedman CA, Barclay ML | title = Review article: comparison of the pharmacokinetics, acid suppression and efficacy of proton pump inhibitors | journal = Alimentary Pharmacology & Therapeutics | volume = 14 | issue = 8 | pages = 963–978 | date = August 2000 | pmid = 10930890 | doi = 10.1046/j.1365-2036.2000.00788.x | s2cid = 45337685 }}</ref>

[[St. John's wort]] (''Hypericum perforatum'') and ''[[GingkoGinkgo biloba]]'' significantly reduce plasma concentrations of omeprazole through [[enzyme induction and inhibition|induction]] of CYP3A4 and CYP2C19.<ref>{{cite journal | vauthors = Izzo AA, Ernst E | title = Interactions between herbal medicines and prescribed drugs: an updated systematic review | journal = Drugs | volume = 69 | issue = 13 | pages = 1777–1798 | year = 2009 | pmid = 19719333 | doi = 10.2165/11317010-000000000-00000 | s2cid = 25720882 }}</ref>

Omeprazole irreversibly blocks the enzyme system on parietal cells that is needed for the secretion of gastric acid. It is a specific H{{sup|+}}/K{{sup|+}}ATPase inhibitor. This is the enzyme needed for the final step in the secretion of gastric acid.<ref name=":0">{{cite journal | vauthors = Howden CW | title = Clinical pharmacology of omeprazole | journal = Clinical Pharmacokinetics | volume = 20 | issue = 1 | pages = 38–49 | date = January 1991 | pmid = 2029801 | doi = 10.2165/00003088-199120010-00003 | s2cid = 25855436 }}</ref>

Omeprazole, as well as other PPIs, are only effective on active H⁺/K⁺-ATPase pumps. These pumps are stimulated in the presence of food to aid in digestion. For this reason, patients should be advised to take omeprazole with a glass of water, on anbefore emptya stomachmeal.<ref>{{cite journal | vauthors = Katz PO, Gerson LB, Vela MF | title = Guidelines for the diagnosis and management of gastroesophageal reflux disease | journal = The American Journal of Gastroenterology | volume = 108 | issue = 3 | pages = 308–28; quiz 329 | date = March 2013 | pmid = 23419381 | doi = 10.1038/ajg.2012.444 | s2cid = 8198975 | doi-access = free }}</ref> Additionally, most sources recommend that after taking omeprazole, at least 30 minutes should be allowed to elapse before eating<ref>{{cite web|url=http://medical-dictionary.thefreedictionary.com/omeprazole|title=Omeprazole, in The Free Medical Dictionary|access-date=11 November 2010|archive-date=12 June 2011|archive-url=https://web.archive.org/web/20110612172513/http://medical-dictionary.thefreedictionary.com/omeprazole|url-status=live}}</ref><ref>{{cite web|url=https://www.drugs.com/monograph/omeprazole.html|title=Omeprazole|publisher=Drugs.com|access-date=11 November 2010|url-status=live|archive-url=https://web.archive.org/web/20110219135631/http://www.drugs.com/monograph/omeprazole.html|archive-date=19 February 2011}}</ref> (at least 60 minutes for immediate-release omeprazole plus sodium bicarbonate products, such as Zegerid),<ref>{{cite web |url=http://www.rxlist.com/zegerid-drug-patient.htm#howtake |title=Zegird, How to take |publisher=rxlist.com |access-date=11 November 2010 |url-status=live |archive-url=https://web.archive.org/web/20101026072806/http://www.rxlist.com/zegerid-drug-patient.htm#howtake |archive-date=26 October 2010}}</ref> though some sources say that with delayed-release forms of omeprazole, waiting before eating after taking the medication is not necessary.<ref>{{cite web | url = http://www.mims.com/page.aspx?menuid=mng&name=omeprazole+omeprazole"Zegerid |OTC titleFDA =label" Omeprazole | work = Essential Drug Information | archive-url = https://web.archive.org/web/20200804223751/https://www.mims.com/page.aspx?menuid=mng&name=omeprazole+omeprazole |archive-date=4 August 2020 | publisher = MIMS USA | access-date = 20 December 2009}} {{verify source|date=January 2011}}</ref>

Omeprazole is completely metabolized by the [[cytochrome P450]] system, mainly in the liver, by [[CYP2C19]] and [[CYP3A4]] [[Isozyme|isoenzymes]].<ref name=Dav2015 /> Identified metabolites are the [[sulfone]], the [[sulfide]], and hydroxy-omeprazole, which exert no significant effect on acid secretion. About 77% of an orally given dose is excreted as metabolites in the urine, and the remainder is found in the feces, primarily originating from bile secretion.<ref name=":1" /> Omeprazole has a half life of 0.5 to 1 hour.<ref name=":1">{{cite web |title=Omeprazole |url=https://www.drugbank.ca/drugs/DB00338 |website=www.drugbank.ca |access-date=29 January 2019 |archive-date=30 January 2019 |archive-url=https://web.archive.org/web/20190130053122/https://www.drugbank.ca/drugs/DB00338 |url-status=live }}</ref> The pharmacological effects of omeprazole last longer as it is covalently bonded to proton pump on parietal cells to induce effects.

[[AstraZeneca]] also [[drug development|developed]] [[esomeprazole]] (Nexium) which is a [[eutomer]], purely the (''S'')-enantiomer, rather than a racemate like omeprazole.{{medcn|date=December 2022}}

Omeprazole was first made in 1979 by Swedish AB Hässle, part of [[Astra AB]]. It was the first of the proton pump inhibitors (PPI).<ref>{{Citecite web|url=https://apps.who.int/medicinedocs/en/d/Js4915e/2.5.html|archive-url=https://web.archive.org/web/20101002080328/http://apps.who.int/medicinedocs/en/d/Js4915e/2.5.html|url-status=dead|archive-date=2 October 2010|title=Trends in Drug Patenting - Case Studies: THE CASES: 5. OMEPRAZOLE|website=apps.who.int|access-date=22 August 2019}}</ref><ref name="Fellenius 1981">{{cite journal | vauthors = Fellenius E, Berglindh T, Sachs G, Olbe L, Elander B, Sjöstrand SE, Wallmark B | title = Substituted benzimidazoles inhibit gastric acid secretion by blocking (H+ + K+)ATPase | journal = Nature | volume = 290 | issue = 5802 | pages = 159–161 | date = March 1981 | pmid = 6259537 | doi = 10.1038/290159a0 | s2cid = 4368190 | bibcode = 1981Natur.290..159F }}</ref> [[Astra AB]], now AstraZeneca, launched it as an ulcer medicine under the name Losec in Sweden. It was first sold in the United States in 1989 under the brand name Losec. In 1990, at the request of the [[Food and Drug Administration|U.S. Food and Drug Administration]], the brand name Losec was changed to Prilosec to avoid confusion with the [[diuretic]] Lasix ([[furosemide]]).<ref name=farley>{{cite journal | vauthors = Farley D | title = Making it easier to read prescriptions | journal = FDA Consumer | volume = 29 | issue = 6 | pages = 25–27 | date = July–August 1995 | pmid = 10143448 | url = http://www.thebody.com/content/art13913.html | url-status = dead | access-date = 26 January 2011 | archive-url = https://web.archive.org/web/20120315172345/http://www.thebody.com/content/art13913.html | archive-date = 15 March 2012 }}</ref> The new name led to confusion between omeprazole (Prilosec) and [[fluoxetine]] (Prozac), an [[antidepressant]].<ref name=farley />

[[Category:AstraZenecaCYP1A2 brandsinducers]]

[[Category:BayerDrugs brandsdeveloped by AstraZeneca]]