What Is Omeprazole? Some Essential Information
What is omeprazole? It is representative of the class of drugs called proton pump inhibitors, used to treat problems such as gastric hyperacidity and gastritis.
In today’s article we aim to introduce you to what omeprazole is, giving you the following information about it:
- The mechanisms of its action
- Pharmacokinetics
- Metabolism
- Side effects
- Interactions with other drugs
- The problems it can treat
What is omeprazole and how does it work?
Due to the hydrochloric acid produced by the parietal cells, the stomach has an acidic pH. This factor is essential for food digestion because gastric acidity:
- Helps to properly break down proteins.
- It breaks down pepsins into peptides, making proteolysis possible, ie breaking the peptide bonds of proteins.
- Prevents bacterial infections, these microorganisms are usually unable to survive in an acidic environment.
Excessive secretion of gastric juices can cause damage to the lining of the gastrointestinal tract. As a result, ulcers form in the stomach and duodenum.
Stages of secretion of gastric juices
The secretion of gastric juices has 3 stages:
- Segregation of H + and Cl – ions in parietal cells.
- Combining them to form hydrochloric acid (HCl) in the channels.
- Segregation of acids from the ducts lining the stomach.
Proton pump inhibitors, such as omeprazole, act in the last stage of gastric juice production. They irreversibly inhibit H + / K + ATPase, a pH-dependent bond with a maximum pH of less than 6.
This inhibition occurs by the formation of a covalent SS bond between sulfamide and a cysteine residue, to which proton pumps have access. The role of omeprazole is to bind residues Ciz-813 and Ces-892.
Pharmacokinetics
Like other proton pump inhibitors, omeprazole is administered in its neutral, inactive form. This form is lipophilic, ie insoluble in water and able to penetrate cell membranes without any problems.
Because these cells have an acidic pH, they convert omeprazole to its active protonated form. Thus, it can perform its functions, irreversibly binding to the proton pump and blocking its action.
- Omeprazole is labile in acidic environments, which is why the oral capsules have an enteric coating.
- The binding of omeprazole to plasma proteins reaches a level of about 95%, which increases its ability to interact with other drugs, as it can withstand a dose change.
- At the same time, this drug will be completely absorbed by the small intestine 3-6 hours after administration.
- The oral bioavailability of omeprazole is approximately 35% and, if administered regularly once daily, may increase to 60%.
- Its volume of distribution is 0.3 l / kg.
the metabolism
Omeprazole is completely metabolised by the liver via the CYP450 system. Its metabolism depends largely on the CYP2C19 isoenzyme.
Most oral doses of omeprazole are excreted in the urine as metabolites and the rest in the faeces from bile secretion.
Side effects
Now that you know what omeprazole is, you need to consider the fact that it can cause various side effects. Although many of these are not the consequence of the selectivity of his action, it is good to remember them. The most important side effects of omeprazole are:
- Severe hypomagnesaemia (in case of prolonged treatment)
- Increased risk of bone fractures
- Skin problems such as itching and hives
- Gastrointestinal changes such as diarrhea, constipation, abdominal pain, nausea or vomiting
- Peripheral neuropathy
- Hypersensitivity
- Hemolytic anemia
- Reduced absorption of vitamin B12 (increases the risk of megaloblastic anemia)
- Increased risk of subacute cutaneous lupus erythematosus
- Increased levels of chromogranin A, a protein associated with certain cancers
Interactions with other drugs
Taken concomitantly, omeprazole may interact with certain medicines, reducing or amplifying their effects.
Among other things, omeprazole reduces the action:
- clopidogrel
- Antifungal drugs
- Phenytoin
- Mycophenolate
Omeprazole may increase the action of some medicines such as:
- Methotrexate
- amphetamines
- benzodiazepines
- Carvedilol
- Citalopram
- Escitalopram
- Cyclosporine
- Warfarin
Because omeprazole may interact with other medicines to avoid complications, seek the advice of a doctor before taking it with any pharmaceutical treatment.
The problems it can treat
You can take omeprazole to treat:
- Gastric ulcers
- Duodenal ulcers
- Esophagitis caused by gastroesophageal reflux
- Zollinger-Ellison syndrome
- Gastritis
- Functional dyspepsia
