Omeprazole (omeprazole) is a specific proton pump inhibitor (PPI) in the parietal cells of the stomach. As a result, it ensures a reversible inhibition of the secretion of hydrochloric acid in the stomach.

How omeprazole works

Oral dosing of omeprazole once daily provides rapid and effective 24/7 inhibition of gastric acid secretion, with maximum effect being achieved after 4 days of dosing.

As a consequence of decreased acid secretion and gastric acidity, omeprazole dose-dependently reduces acid exposure of the esophagus in patients with gastro-oesophageal reflux disease.

Indications for the use of omeprazole

Omeprazole is used in cases such as:

  • treatment of duodenal ulcer,
  • duodenal ulcer relapse prevention,
  • treatment of stomach ulcers,
  • to prevent relapse of gastric ulcers,
  • in combination with appropriate antibiotics, Helicobacter pylori eradication therapy in peptic ulcer disease,
  • treatment of gastric and duodenal ulcers associated with taking NSAIDs (non-steroidal anti-inflammatory drugs),
  • prevention of gastric and duodenal ulcers associated with NSAIDs in patients at risk of their development,
  • treatment of reflux oesophagitis,
  • long-term maintenance treatment of patients after healing from reflux oesophagitis,
  • treatment of symptomatic gastro-oesophageal reflux disease,
  • treatment of Zollinger-Ellison syndrome (a complex of complications of excessive acid secretion by the gastric mucosa, caused by a gastrin-secreting neuroendocrine tumor, most often located in the pancreas or duodenum).

Contraindications to the use of omeprazole

Hypersensitivity to omeprazole. Omeprazole, like other proton pump inhibitors, should not be used concomitantly with nelfinavir (nelfinavir is a protease inhibitor - an enzyme that is involved in the multiplication of HIV).

Available preparations

Omeprazole and omeprazole magnesium are not persistent in the environmentacidic and therefore are available in the form of capsules or tablets filled with special coated pellets in the following doses: 10 mg, 20 mg and 40 mg.

Omeprazole dosage

The dosage is determined by the gastroenterologist depending on the indications, age and comorbidities.

Side effects of omeprazole

The most common side effects of omeprazole include:

  • headaches,
  • stomach pains,
  • constipation,
  • diarrhea,
  • flatulence,
  • nausea,
  • vomiting.

Severe hypomagnesaemia (too low blood magnesium) has been reported in patients treated with proton pump inhibitors such as omeprazole. Symptoms such as:

  • fatigue,
  • tetany,
  • delirium,
  • dizziness
  • and ventricular arrhythmias.

In patients expected to be on long-term therapy or taking proton pump inhibitors, including digoxin or other drugs that may cause hypomagnesaemia (e.g. diuretics), pre-treatment and periodic blood magnesium measurements should be considered. measurements during treatment.

Omeprazole, like all drugs that inhibit gastric acid secretion, may also reduce the absorption of vitamin B12 (cyanocobalamin).

Proton pump inhibitors, especially when used in high doses and in long-term therapy (over 1 year), may slightly increase the risk of fracture in the hip, wrist and spine, especially in the elderly or in patients with other medical diagnoses. risk factors.

Taking proton pump inhibitors may also lead to a slightly increased risk of gastrointestinal infections such as Salmonella and Campylobacter.

In the event of any alarming symptoms (e.g., significant unintentional weight loss, recurrent vomiting, difficulty in swallowing, haematemesis or tarry stools), and in the case of suspected or presence of gastric ulcer, the presence of neoplastic changes should be excluded. omeprazole can alleviate symptoms and delay diagnosis.

Interaction with other drugs and substances

  • When co-administered with omeprazole, the plasma concentrations of nelfinavir and atazanavir are reduced. Concomitant use of omeprazole with nelfinavir is contraindicated;
  • Co-administration of omeprazole (20 mg daily) and digoxin resulted in a 10% increase indigoxin bioavailability;
  • The results of studies indicate that the combination of clopidogrel and omeprazole may reduce the concentration of the active metabolite of clopidogrel in the body;
  • Absorption of posaconazole, erlotinib, ketoconazole and itraconazole is significantly reduced and therefore their clinical efficacy may be reduced;
  • Omeprazole is a moderate inhibitor of CYP2C19. Therefore, the metabolism of concomitantly administered active substances, also metabolised by CYP2C19, may be reduced and the systemic exposure to these drugs may be increased. Such substances include, but are not limited to: R-warfarin and other vitamin K antagonists, cilostazol, diazepam and phenytoin.
  • Increased serum concentrations of tacrolimus have been reported when used concomitantly with omeprazole;
  • Concomitant voriconazole treatment resulted in more than doubling of the omeprazole exposure. Dose adjustment should be considered in patients with severe hepatic impairment and when long-term treatment is indicated;
  • Inducers of CYP2C19 and / or CYP3A4 Active substances known to induce CYP2C19 or CYP3A4 or both (such as rifampicin and St John's wort) may lead to decreased omeprazole serum levels by increasing omeprazole's rate of metabolism.

Impact on driving

Omperazole has no influence on the ability to drive and use machines. However, adverse drug reactions such as dizziness and visual disturbances may occur.

If affected, patients should not drive or use machines.

Pregnancy and breastfeeding

Study results show no adverse effects of omeprazole on pregnancy or on the he alth of the fetus / newborn child. Omeprazole can be used during pregnancy. Omeprazole passes into breast milk, but there is no risk of any negative effects on the child when using the drug in therapeutic doses.

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