Omeprazole

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Omeprazole

Omeprazole (INN

International Nonproprietary Name

An International Nonproprietary Name is the official non-proprietary or generic name given to a pharmaceutical substance, as designated by the World Health Organization ....
) is a proton pump inhibitor

Proton pump inhibitor

Proton pump inhibitors are a group of Medications whose main action is a pronounced and long-lasting reduction of gastric acid production. They are the most potent inhibitors of acid secretion available today....
used in the treatment of dyspepsia

Dyspepsia

Dyspepsia , popularly known as indigestion, meaning hard or difficult digestion, is a medical condition characterized by chronic or recurrent pain in the upper abdomen, upper abdominal fullness and feeling full earlier than expected when eating....
, peptic ulcer disease

Peptic ulcer

A peptic ulcer, also known as ulcus pepticum, PUD or peptic ulcer disease, is an ulcer of an area of the gastrointestinal tract that is usually acidic and thus extremely painful....
(PUD), gastroesophageal reflux disease

Gastroesophageal reflux disease

Gastroesophageal reflux disease ', Gastro-oesophageal reflux disease ', Gastric reflux disease, or Acid reflux disease is defined as chronic symptoms or mucosal damage produced by the abnormal reflux in...
(GORD/GERD) and Zollinger-Ellison syndrome

Zollinger-Ellison syndrome

Zollinger-Ellison syndrome is a disorder where increased levels of the hormone gastrin are produced, causing the stomach to produce excess hydrochloric acid....
. It was first marketed in the US in 1989 by AstraZeneca

AstraZeneca

AstraZeneca plc , is a large Anglo-Swedish pharmaceutical company formed on 6 April 1999 by the remerger of Swedish Astra AB and British Zeneca Group plc....
as the magnesium

Magnesium

Magnesium is a chemical element with the symbol Mg, atomic number 12, atomic weight 24.3050 and common oxidation number +2.Magnesium, an alkaline earth metal, is the ninth most abundance of the chemical elements in the universe by mass....
salt

Salt

A salt, in chemistry, is defined as the product formed from the neutralisation reaction of acids and base . Salts are ionic compounds composed of cations and anions so that the product is electrically electric charge ....
omeprazole magnesium under the brand names Losec and Prilosec, and is now also available from generic

Generic drug

A generic drug is a medication which isproduced and distributed without patent protection. The generic drug may still have a patent on the formulation but not on the active ingredient....
manufacturers under various brand names. Omeprazole is one of the most widely prescribed drugs internationally and is available over the counter in some countries.

razole is a racemate.

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Pharmacology

Omeprazole is a racemate. It contains a tricoordinated sulfur atom in a pyramidal structure and therefore can exist in equal amounts of both the S and R enantiomers. In the acidic conditions of the stomach, both are converted to achiral products, which reacts with a cysteine group in H⁺/K⁺ ATPase

Hydrogen potassium ATPase

Gastric hydrogen potassium ATPase is also known as H+/K+ ATPase...
, thereby inhibiting the ability of the parietal cell

Parietal cell

Parietal cells, or oxyntic cells, are the stomach epithelium cell s that secrete gastric acid and intrinsic factor....
s to produce gastric acid

Gastric acid

Gastric acid is one of the main secretions of the stomach, together with several enzymes and intrinsic factor. Chemically it is an acid solution with a pH of 1 to 2 in the stomach lumen , consisting mainly of hydrochloric acid , and large quantities of potassium chloride and sodium chloride ....
.

Facing the loss of patent protection and competition from generic drug

Generic drug

AstraZeneca

AstraZeneca plc , is a large Anglo-Swedish pharmaceutical company formed on 6 April 1999 by the remerger of Swedish Astra AB and British Zeneca Group plc....
developed and heavily marketed esomeprazole

Esomeprazole

Esomeprazole is a proton pump inhibitor developed and marketed by AstraZeneca which is used in the treatment of dyspepsia, peptic ulcer , gastroesophageal reflux disease and Zollinger-Ellison syndrome....
(Nexium) as a replacement. Esomeprazole is the S-enantiomer in the pure form.

According to AstraZeneca

AstraZeneca

AstraZeneca plc , is a large Anglo-Swedish pharmaceutical company formed on 6 April 1999 by the remerger of Swedish Astra AB and British Zeneca Group plc....
, omeprazole undergoes a chiral shift

Chirality (chemistry)

The term chiral is used to describe an object that is non-Superposition on its mirror image.Human hands are perhaps the most universally recognized example of chirality: The left hand is a non-superposable mirror image of the right hand; no matter how the two hands are oriented, it is impossible for all the major features of both hands...
in vivo

In vivo

In vivo means that which takes place inside an organism. In science, in vivo refers to experimentation done in or on the living tissue of a whole, living organism as opposed to a partial or dead one or a in vitro....
which converts the inactive R-enantiomer to the active S-enantiomer doubling the concentration of the active form. This chiral shift is accomplished by the CYP2C19

CYP2C19

Cytochrome P450 2C19 , a member of the cytochrome P450 mixed-function oxidase system, is involved in the metabolism of xenobiotics in the body. It is involved in the metabolism of several...
isozyme

Isozyme

Isozymes are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. These enzymes usually display different kinetic parameters , or different regulatory properties....
of cytochrome P450, which is not found equally in all human populations. Those who do not metabolize the drug effectively are called "poor metabolizers." The approximate proportion of the poor metabolizer phenotype

Phenotype

A phenotype is any observable characteristic or trait_ of an organism: such as its morphology , development, biochemical or physiological properties, or behavior....
in different populations is as follows:

Caucasians 10%
Asian 20%
South Pacific Islands 70%

In theory, by using pure esomeprazole the effect on the proton pump will be equal in all patients, eliminating the "poor metabolizer effect".

Name change

In 1990, at the request of the United States

United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
Food and Drug Administration

Food and Drug Administration

The U.S. Food and Drug Administration is an Government agency of the United States Department of Health and Human Services and is responsible for regulating and supervising the safety of foods, dietary supplements, Medications, vaccines, Biopharmaceutical, blood transfusion, medical devices, Electromagnetic radiation-emitting devices, veteri...
(FDA), the brand name Losec was changed to Prilosec to avoid confusion with the diuretic

Diuretic

A diuretic is any drug that elevates the rate of urination and thus provides a means of forced diuresis. There are several categories of diuretics....
Lasix (furosemide

Furosemide

Furosemide or frusemide is a loop diuretic used in the treatment of congestive heart failure and edema. It is most commonly marketed by Sanofi-Aventis under the brand name Lasix....
). Unfortunately, the new name has led to confusion between omeprazole (Prilosec) and fluoxetine

Fluoxetine

Fluoxetine hydrochloride is an antidepressant of the selective serotonin reuptake inhibitor class. Fluoxetine is approved for the treatment of major depressive disorder , obsessive-compulsive disorder , bulimia nervosa, anorexia nervosa, panic disorder and premenstrual dysphoric disorder....
(Prozac), an antidepressant

Antidepressant

An antidepressant is a psychiatric medication used for alleviating major depressive disorder or dysthymia. Drug groups known as MAOIs, tricyclics, and second-generation antidepressants such as SSRIs, and serotonin-norepinephrine reuptake inhibitors are particularly associated with the term....
.

Clinical use

Use in Helicobacter pylori eradication

Omeprazole is combined with the antibiotics clarithromycin

Clarithromycin

Clarithromycin is a macrolide antibiotic used to treat pharyngitis, tonsillitis, acute maxillary sinusitis, acute bacterial exacerbation of chronic bronchitis, pneumonia , skin and skin structure infections, and, in HIV and AIDS patients to prevent, and to treat, disseminated Mycobacterium avium complex ....
and amoxicillin

Amoxicillin

Amoxicillin or amoxycillin is a moderate-spectrum, bacteriolytic, beta-lactam antibiotic used to treat bacterial infections caused by susceptible microorganisms....
(or metronidazole

Metronidazole

Metronidazole is a nitroimidazole antibiotic medication used mainly in the treatment of infections caused by susceptible organisms, particularly anaerobe bacterium and protozoa....
in penicillin-hypersensitive patients) in the 7-14 day eradication triple therapy for Helicobacter pylori
Helicobacter pylori

Helicobacter pylori is a Gram-negative, microaerophile bacterium that inhabits various areas of the stomach and duodenum. It causes a chronic low-level inflammation of the stomach lining and is strongly linked to the development of duodenal and gastric peptic ulcers and stomach cancer bacteria....
. Infection by H. pylori is the causative factor in the majority of peptic

Peptic ulcer

Dosage forms

Omeprazole is available as tablets and capsules (containing omeprazole or omeprazole magnesium) in strengths of 10 mg, 20 mg, and in some markets 40 mg; and as a powder (omeprazole sodium) for intravenous injection. Most oral omeprazole preparations are enteric-coated

Enteric coating

An enteric coating is a barrier applied to oral medication that controls the location in the digestive system where it is absorbed. Enteric refers to the small intestine, therefore enteric coatings prevent release of medication before it reaches the small intestine....
, due to the rapid degradation of the drug in the acid

Acid

An acid is traditionally considered any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion Activity greater than in pure water, i.e....
ic conditions of the stomach

Stomach

In most mammals, the stomach is a hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication....
. This is most commonly achieved by formulating enteric-coated granules within capsules, enteric-coated tablets, and the multiple-unit pellet system.

It is also available for use in injectable form (I.V.) in Europe, but not in the U.S. The injection pack is a combination pack consisting of a vial and a separate ampule of reconstituting solution. Each 10 ml clear glass vial contains a white to off-white lyophilised powder consisting of omeprazole sodium 42.6 mg equivalent to 40 mg of omeprazole.

Losec is manufactured by AstraZeneca

AstraZeneca

AstraZeneca plc , is a large Anglo-Swedish pharmaceutical company formed on 6 April 1999 by the remerger of Swedish Astra AB and British Zeneca Group plc....
, Södertälje, Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic countries on the Scandinavian Peninsula in Northern Europe. Sweden has land borders with Norway to the west and Finland to the northeast, and it is connected to Denmark by the ?resund Bridge in the south....
.

Multiple unit pellet system

Omeprazole tablets manufactured by AstraZeneca (notably Losec/Prilosec) are formulated as a "multiple unit pellet system" (MUPS). Essentially, the tablet

Tablet

A tablet is a mixture of active substances and excipients, usually in Powder form, pressed or compacted into a solid. The excipients include binders, glidants and lubricants to ensure efficient tabletting; disintegrants to ensure that the tablet breaks up in the digestive tract; sweeteners or flavours to mask the taste of bad-tasting activ...
consists of extremely small enteric-coated granules (pellets) of the omeprazole formulation inside an outer shell. When the tablet is immersed in an aqueous solution, as happens when the tablet reaches the stomach, water enters the tablet by osmosis

Osmosis

Osmosis is the diffusion of a solvent through a Semipermeable membrane, from a solution of low solute concentration to a solution with high solute concentration , up a solute concentration gradient....
. The contents swell from water absorption causing the shell to burst, releasing the enteric-coated granules. For most patients, the multiple-unit pellet system is of no advantage over conventional enteric-coated preparations. Patients for which the formulation is of benefit include those requiring nasogastric tube feeding and those with difficulty swallowing (dysphagia

Dysphagia

Dysphagia is the medical term for the symptom of difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, the term is sometimes used as a condition in its own right....
).

The granules are manufactured in a fluid air bed system. Sugar spheres in suspension are sequentially sprayed with aqueous suspension

Suspension (chemistry)

In chemistry, a suspension is a heterogeneous fluid containing solid particles that are sufficiently large for sedimentation. Usually they must be larger than 1 micrometre....
s of omeprazole, a protective layer, an enteric coating and an outer layer to reduce granule aggregation. The granules are mixed with other excipient

Excipient

An excipient is an inactive substance used as a carrier for the active ingredients of a medication. In many cases, an "active" substance may not be easily administered and absorbed by the human body; in such cases the substance in question may be dissolved into or mixed with an excipient....
s and compressed into tablets. Finally, the tablets are film-coated to improve the stability and appearance of the preparation.

Immediate release formulation

In June 2004 the FDA approved an immediate release preparation of omeprazole and sodium bicarbonate

Sodium bicarbonate

Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula NaHCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder....
that does not require an enteric coating. This preparation employs sodium bicarbonate as a buffer to protect omeprazole from gastric acid degradation. This allows for the production of chewable tablets. This combination preparation is marketed in the United States by Santarus under the trade name Zegerid. Zegerid is marketed as capsules, chewable tablets, and powder for oral suspension. Zegerid is most useful for those patients who suffer from nocturnal acid breakthrough (NAB) or those patients who desire immediate relief. In India it is marketed by Dr Reddy's Labs as powder formulation with the brand name OMEZ-INSTA. It is reported to have additional benefits with patients suffering from alcoholic gastritis and life-style associated gastritis.

Side effects

As with all proton pump inhibitors, omeprazole is generally well tolerated. Some of the most frequent side effects

Adverse drug reaction

An adverse drug reaction or adverse drug event is an expression that describes the unwanted, negative consequences associated with the use of given medications....
of omeprazole (experienced by over 1% of those taking the drug) are headache

Headache

In medicine a headache or wiktionary:cephalalgia is a symptom of a number of different conditions of the head and sometimes neck. Some of the causes are benign while others are medical emergencies....
, diarrhea

Diarrhea

In medicine, diarrhea, also spelled diarrhoea , is characterized by frequent loose or liquid bowel movements. The spelling of "diarrhea" is an appropriation of the Greek "diarrhoia" meaning "a flowing through." ....
, abdominal pain, nausea

Nausea

Nausea is the sensation of unease and discomfort in the stomach with an urge to vomit....
, dizziness

Dizziness

Dizziness describes a number of subjective symptoms, which the patient may describe as feelings of lightheadedness, floating, wooziness, giddiness, confusion, disorientation or loss of balance....
, trouble awakening and sleep deprivation, although in clinical trial

Clinical trial

In health care, clinical trials are conducted to allow safety and efficacy data to be collected for new drugs or devices. These trials can only take place once satisfactory information has been gathered on the quality of the product and its non-clinical safety, and Institutional review board approval is granted in the country where the trial...
s the incidence of these effects with omeprazole was mostly comparable to that found with placebo

Placebo

The placebo effect is a phenomenon in medicine where the results of a medical treatment are affected by their symbolism, and not just their medical value....
.

Proton pump inhibitors may be associated with a greater risk of hip fractures , clostridium difficile

Clostridium difficile

Clostridium difficile , also known as "CDF/cdf", or "C. diff", is a species of Gram-positive bacteria of the genus Clostridium. Clostridia are Anaerobic organism, endospore-forming rods ....
diarrhea and heart problems, including cardiac arrest.

Interactions

Patients who are taking Plavix in combination with proton pump inhibiting drugs may be at a greater risk of stroke or heart attack

Absorption and distribution

The absorption of omeprazole takes place in the small intestine and is usually completed within 3-6 hours. The systemic bioavailability

Bioavailability

In pharmacology, bioavailability is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetics properties of medication....
of omeprazole after repeated dose is about 60%. Concomitant intake of food has no influence on the bioavailability. Plasma protein binding is about 95%.

Metabolism and excretion

Omeprazole is completely metabolised by the cytochrome P450 system, mainly in the liver. Identified metabolites are the sulfone

Sulfone

A sulfone is a chemical compound containing a sulfonyl functional group attached to two carbon atoms. The central sulfur atom is twice double bonded to oxygen and has two further hydrocarbon substituents....
, the sulfide

Sulfide

The term sulfide refers to several types of chemical compounds containing sulfur in its lowest oxidation number of −2.Formally, "sulfide" is the dianion, S2−, which exists in strongly alkaline aqueous solutions formed from H2S or alkali metal salts such as Li2S, Na2S, and K2...
and hydroxy-omeprazole, which exert no significant effect on the acid secretion. About 80% of an orally given dose is excreted as metabolites in the urine and the remainder is found in the faeces, primarily originating from bile secretion.

Brand names

Antra in Italy
Famodyl ( Dominican Republic)
Gasec (Mepha)
Gastrazole (Egypt)
Lopraz
Losepine (Pinewood Healthcare, Ireland
Ireland

Ireland is the List of islands by area in Europe, and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islet....
)
Losec worldwide.
Maxpro ( Renata Ltd., bangladesh)
Miracid (Thailand)
Nexium (esomeprazole
Esomeprazole

Esomeprazole is a proton pump inhibitor developed and marketed by AstraZeneca which is used in the treatment of dyspepsia, peptic ulcer , gastroesophageal reflux disease and Zollinger-Ellison syndrome....
, a S-enantiomer
Enantiomer

In chemistry, an enantiomer is one of two stereoisomers that are Superpose complete mirror images of each other, much as one's left and right Chirality are "the same" but opposite....
of omeprazole)
Ocid (India)
Ocid (Zydus Cadila)
Odasole Caps/ Inj. (Greece & Sudan)
Omep (Sandoz
Sandoz

Sandoz is the generic drug subsidiary of Novartis, a multinational pharmaceutical company. The company develops, manufactures and markets off-patent medicines as well as pharmaceutical and biotechnological active ingredients....
)
Omepradex-Z (Dexxon, Israel
Israel

Israel officially the State of Israel , is a country in the Middle East located on the eastern shore of the Mediterranean Sea. It borders Lebanon in the north, Syria in the northeast, Jordan in the east, and Egypt on the southwest, and contains geographically diverse features within its relatively small area....
)
Acimax, Losec, Omepral (Australia)
Omeprol (Serbia)
Omepron (Philippines)
Omesec (CCM, Malaysia)
Ometid(Opsonin Pharma Ltd, Bangladesh)
OMEZ (Dr Reddy's Laboratories Ltd)- FGP
Omezol (Bosch Pharmaceuticals, Pakistan)
Ompic (Pharma Corp Inc, India)
ONIZ 20 (Nepal, Nepal Pharmaceuticals)
Ortanol (Lek Polska Sp. z o.o.)
Ozid (in Indonesia)
Procepin (OMEPRAZOLE in Singapore)
Prilosec, Prilosec OTC, Omez
RISEK (GETZ PHARMA)
Ucetal (SERRAL, Mexico)
Ulcesep (Middle East)
Zegerid (powder for suspension and capsules)
OM(Ambee pharmaceuticals ltd.)

Omeprazole

Pharmacology

Name change

Clinical use

Use in Helicobacter pylori eradication

Dosage forms

Multiple unit pellet system

Immediate release formulation

Side effects

Interactions

Absorption and distribution

Metabolism and excretion

Brand names

External links