OZOL

Originally approved by the

FDA in 1989, omeprazole is a proton-pump inhibitor, used to treat gastric acid-related disorders.

These disorders may include gastroesophageal reflux disease (GERD), peptic ulcer disease, and other diseases characterized by the oversecretion of gastric acid.

This drug was the first clinical useful drug in its class, and its approval was followed by the formulation of many other proton pump inhibitor drugs 6.

Omeprazole is generally effective and well-tolerated, promoting its popular use in children and adults Label.

• Treatment of active duodenal ulcer in adults.

• Eradication of Helicobacter pylori to reduce the risk of duodenal ulcer

recurrence in adults.

• Treatment of active benign gastric ulcer in adults.

• Reduction of risk of upper gastrointestinal (GI) bleeding in critically ill adult patients.

• Treatment of symptomatic gastroesophageal reflux disease (GERD)

patients 1 year of age and older.

• Treatment of erosive esophagitis (EE) due to acid-mediated GERD

patients 1 month of age and older.

• Maintenance of healing of EE due to acid-mediated GERD in patients 1

year of age and older.

• Pathologic hypersecretory conditions in adults

Effects on gastric acid secretion

This drug decreases gastric acid secretion Label.

After oral administration, the onset of the antisecretory effect of omeprazole is usually achieved within one hour, with the maximum effect occurring by 2 hours after administration.

The inhibitory effect of omeprazole on acid secretion increases with repeated once-daily dosing, reaching a plateau after four days Label.

Effects on serum gastrin

In studies of 200 or more patients, serum gastrin levels increased during the first 1-2 weeks of daily administration of therapeutic doses of omeprazole.

This occurred in a parallel fashion with the inhibition of acid secretion.

No further increase in serum gastrin occurred with continued omeprazole administration.

Increased gastrin causes enterochromaffin-like cell hyperplasia and increased serum Chromogranin A (CgA) levels.

The increased

CgA levels may lead to false positive results in diagnostic studies for neuroendocrine tumors Label.

Enterochromaffin-like (ECL) cell effects Human gastric biopsy samples have been obtained from more than 3000 pediatric and adult patients treated with omeprazole in long-term clinical studies.

The incidence of enterochromaffin-like cell hyperplasia in these studies increased with time; however, no case of ECL cell carcinoids, dysplasia, or neoplasia have been identified in these patients.

These studies, however, are of insufficient in power and duration to draw conclusions on the possible influence of long-term administration of omeprazole in the development of any premalignant or malignant conditions Label.

Other effects

Systemic effects of omeprazole in the central nervous system, cardiovascular and respiratory systems have not been found to date.

Omeprazole, given in oral doses of 30 or 40 mg for 2-4 weeks, showed no effect on thyroid function, carbohydrate metabolism, or circulating levels of parathyroid hormone, cortisol, estradiol, testosterone, prolactin, cholecystokinin or secretin Label.

Omeprazole delayed-release capsules contain an enteric-coated granule formulation of omeprazole (because omeprazole is acid-labile), so that absorption of omeprazole begins only after the granules exit the stomach Label.

Absorption of omeprazole occurs rapidly, with peak plasma concentrations of omeprazole achieved within 0.5-3.5 hours Label.

Absolute bioavailability (compared with intravenous administration) is approximately 30-40% at doses of 20-40 mg, largely due to pre-systemic metabolism.

The bioavailability of omeprazole increases slightly upon repeated administration of omeprazole delayed-release capsules Label.

Approximately 0.3 L/kg, corresponding to the volume of extracellular water 5.

Omeprazole is heavily metabolized in the liver by the cytochrome P450 (CYP) enzyme system.

The main part of its metabolism depends on the polymorphically expressed CYP2C19, which is responsible for the formation of hydroxyomeprazole, the major metabolite found in plasma.

The remaining part depends on

CYP3A4, responsible for the formation of omeprazole sulphone Label.

Hover over products below to view reaction partners Omeprazole 5-Hydroxyomeprazole 5'-O-Desmethyl omeprazole Omeprazole sulfone 3-Hydroxyomeprazole.

After a single dose oral dose of a buffered solution of omeprazole, negligible (if any) amounts of unchanged drug were excreted in urine.

Most of the dose (about 77%) was eliminated in urine as at least six different metabolites.

Two metabolites were identified as hydroxyomeprazole and the corresponding carboxylic acid.

The remainder of the dose was found in the feces.

This suggests significant biliary excretion of omeprazole metabolites.

Three metabolites have been identified in the plasma, the sulfide and sulfone derivatives of omeprazole, and hydroxyomeprazole.

These metabolites possess minimal or no antisecretory activity Label.

0.5-1 hour (healthy subjects, delayed-release capsule) Label Approximately 3 hours (hepatic impairment) Label.

Healthy subject (delayed release capsule), total body clearance 500-600 mL/min Label Geriatric plasma clearance: 250 mL/min Label Hepatic impairment plasma clearance: 70 mL/min Label.

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Oral acute (LD50) : 4000 mg/kg (mouse), 2210 mg/kg (rat) MSDS.

Symptoms of overdose include confusion, drowsiness, blurred vision, tachycardia, nausea, diaphoresis, flushing, headache, and dry mouth.

Carcinogenesis and mutagenesis

In 24-month studies in rats, a dose-related significant increase in gastric carcinoid tumors and ECL cell hyperplasia was seen in male and female animals.

Carcinoid tumors have also been found in rats treated with a fundectomy or long-term treatment with other proton pump inhibitors, or high doses of H2-receptor antagonists Label.

Omeprazole showed positive clastogenic effects in an in vitro human lymphocyte chromosomal aberration study, in one of two in vivo mouse micronucleus tests, and in an in vivo bone marrow cell chromosomal aberration test.

Omeprazole tested negative in the in vitro Ames test, an in vitro mouse lymphoma cell forward mutation assay, and an in vivo rat liver DNA damage assay Label.

The use in breastfeeding

Limited data indicate that omeprazole may be present in human milk.

There is currently no information on the effects of omeprazole on the breastfed infant or production of milk.

The benefits of breastfeeding should be considered along with the level of need for omeprazole and any potential adverse effects on the breastfed infant from omeprazole Label.

Effects on fertility

Effects of omeprazole at oral doses up to 138 mg/kg/day in rats (about 34 times an oral human dose) was found to have no impact on fertility and reproductive performance Label.

Allergy alert: do not use if you are allergic to omeprazole omeprazole may cause severe skin reactions.

Symptoms may include: skin reddening blisters rash If an allergic reaction occurs, stop use and seek medical help right away.

Do not use if you have: trouble or pain swallowing food, vomiting with blood, or bloody or black stools heartburn with lightheadedness, sweating or dizziness chest pain or shoulder pain with shortness of breath; sweating; pain spreading to arms, neck or shoulders; or lightheadednes frequent chest pain These may be signs of a serious condition.

See your doctor.

Ask a doctor before use if you have: had heartburn over 3 months.

This may be a sign of a more serious condition. frequent wheezing, particularly with heartburn unexplained weight loss nausea or vomiting stomach pain Ask a doctor or pharmacist before use if you are taking a prescription drug.

Acid reducers may interact with certain prescription drugs.

Stop use and ask doctor if: your heartburn continues or worsens you need to take this product for more than 14 days you need to take more than 1 course of treatment every 4 months you get diarrhea you develop a rash or joint pain If pregnant or breast-feeding, ask a health professional before use.

Keep out of reach of children.

In case of overdose, get medical help or contact a Poison Control Center right away.

Directions for adults 18 years of age and older this product is to be used once a day (every 24 hours), every day for 14 days it may take to 4 days for full effect; some people get complete relief of symptoms within 24 hours 14-Day Course of Treatment swallow 1 tablet with a glass of water before eating in the morning take every day for 14 days do not take more than 1 tablet a day do not use for more than 14 days unless directed by your doctor swallow whole.

Do not chew or crush tablets

Repeated 14-Day Courses (if needed) you may repeat a 14-day course every 4 months do not take for more than 14 days or more often than every 4 months unless directed by a doctor children under 18 years of age: ask a doctor.

Heartburn in children may sometimes be caused by a serious condition.