Ulcomez

Mechanism of action

Carbonate ions participate in buffering reactions that help maintain pH homeostasis in biological systems. They can react with acids to form bicarbonate and carbon dioxide, thus neutralizing excess acidity in the body. This mechanism is crucial in processes such as respiration and metabolism.

Pharmacodynamics

As a buffer, carbonate helps to stabilize pH levels in different biological environments, preventing excessive acidity or alkalinity that could impair cellular functions. It is involved in the transport of carbon dioxide in the blood and plays a role in maintaining the acid-base equilibrium necessary for physiological processes.

Pharmacokinetics

Carbonate ions are readily absorbed in the gastrointestinal tract when ingested and can be found in various body fluids. They are involved in the bicarbonate buffering system, where they are converted to bicarbonate (HCO3-) and carbon dioxide (CO2) through reactions with acids. The kidneys regulate the levels of bicarbonate and carbonate in the body, excreting or reabsorbing them as needed to maintain homeostasis.

Pregnancy

There is no specific information available regarding the use of carbonate compounds during pregnancy. Consult a healthcare provider for advice.

Breast-feeding

There is no specific information available regarding the use of carbonate compounds while breastfeeding. Consult a healthcare provider for advice.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Indications

• Gastric ulcer
• Duodenal ulcer
• Gastro-oesophageal reflux disease (GERD)
• Severe oesophagitis
• Helicobacter pylori eradication (in combination therapy)
• Prevention of NSAID-associated gastric and duodenal ulcers
• Zollinger-Ellison syndrome

Dosage

Adults: The usual dose for adults is 20 mg once daily for 4 weeks for duodenal ulcer and GERD. For gastric ulcer, the dose may be 20 mg to 40 mg once daily

Mechanism of action

Omeprazole works by specifically binding to the proton pump (H+/K+ ATPase) in the gastric parietal cells, leading to irreversible inhibition of acid secretion. This binding prevents the exchange of hydrogen ions for potassium ions, effectively reducing the production of gastric acid and promoting healing of acid-related conditions.

Pharmacodynamics

The pharmacodynamic effects of omeprazole manifest as a significant decrease in gastric acidity, which improves symptoms related to excessive acid secretion. The onset of action typically occurs within an hour of administration, with maximum effect seen within 2 to 4 days of continuous use. The duration of action allows for once-daily dosing in most indications.

Pharmacokinetics

Omeprazole is rapidly absorbed from the gastrointestinal tract, reaching peak plasma concentrations within 0.5 to 3.5 hours after oral administration. It is extensively metabolized in the liver via the cytochrome P450 system, primarily CYP2C19 and CYP3A4, leading to the formation of inactive metabolites. The elimination half-life is approximately 0.5 to 1 hour, but the effects on gastric acid secretion last much longer due to the irreversible nature of proton pump inhibition. Omeprazole is excreted mainly in the urine as metabolites, with less than 1% of the drug excreted unchanged.

Contra-indications

• Hypersensitivity to omeprazole or any component of the formulation
• Use with caution in patients with severe liver impairment

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Headache
• Abdominal pain
• Flatulence
• Constipation
• Dizziness
• Fatigue
• Rash
• Muscle weakness
• Gastrointestinal candidiasis
• Aggression
• Agitation
• Bronchospasm
• Encephalopathy

Interactions

• Cenobamate may increase exposure to omeprazole
• Fedratinib may increase exposure to omeprazole
• Apalutamide may decrease exposure to omeprazole
• Cilostazol may increase exposure to omeprazole

Precautions

• Monitor patients for gastrointestinal symptoms
• Use caution in patients with a history of liver disease
• Consider potential for vitamin B12 deficiency with long-term use
• Monitor for signs of Clostridium difficile infection in the colon

Pregnancy

Not known to be harmful during pregnancy, but should be used only if clearly needed.

Breast-feeding

Excreted in breast milk, caution is advised when administered to nursing mothers.

Storage

Store below 25 degrees Celsius. Protect from moisture. Keep out of reach of children.

Formulations

• Orodispersible tablets
• Gastro-resistant capsules
• Intravenous injection
• Oral suspension