Losec

Losec contains omeprazole, a proton pump inhibitor (PPI) widely prescribed for the treatment and prevention of acid-related gastrointestinal disorders.

Indications include gastro-oesophageal reflux disease (GORD), erosive oesophagitis, gastric and duodenal ulcers, Zollinger-Ellison syndrome, and as part of Helicobacter pylori eradication regimens in combination with antibiotics.

Omeprazole irreversibly inhibits the hydrogen-potassium ATPase proton pump on gastric parietal cells, the final common pathway in acid secretion.

This produces a profound and sustained reduction in basal and stimulated acid output.

A single daily dose of 20 mg reduces 24-hour intragastric acidity by approximately 80 per cent, and the effect persists until new proton pumps are synthesised.

Losec capsules contain enteric-coated granules that protect the active ingredient from degradation in gastric acid, ensuring release in the alkaline environment of the duodenum where absorption occurs.

Losec remains one of the most commonly prescribed PPIs worldwide and is available in capsule form as well as an intravenous formulation for hospital use.

Take Losec once daily, preferably in the morning, at least 30 minutes before breakfast. Swallow the capsule whole with a glass of water; do not chew or crush it.

If you have difficulty swallowing capsules, they may be opened and the granules mixed with a small amount of slightly acidic liquid (such as fruit juice or yoghurt) and swallowed immediately without chewing.

For H. pylori eradication, omeprazole is taken twice daily alongside prescribed antibiotics for seven days. For ulcer healing, a course of four to eight weeks is typical.

For long-term GORD maintenance, your doctor will aim to use the lowest effective dose.

For GORD: 20 mg once daily for four to eight weeks. Severe oesophagitis: 40 mg daily for up to eight weeks. Maintenance: 10 to 20 mg daily. Duodenal ulcer healing: 20 mg daily for four weeks.

Gastric ulcer healing: 20 mg daily for eight weeks. H. pylori eradication: 20 mg twice daily with antibiotics for seven days.

Zollinger-Ellison syndrome: starting dose 60 mg daily, adjusted as needed. For hepatic impairment, 10 to 20 mg daily is sufficient. No dose adjustment for renal impairment.

Common side effects (1 in 10 to 1 in 100 patients) include headache, abdominal pain, nausea, diarrhoea, constipation, and flatulence.

Uncommon effects include dizziness, paraesthesia, dry mouth, rash, and elevated liver enzymes. Sleep disturbances and taste alteration may also occur.

Long-term PPI use (over one year) has been associated with hypomagnesaemia, vitamin B12 deficiency, increased risk of Clostridium difficile infection, and a small increase in hip, wrist, and spinal fracture risk, particularly at higher doses in elderly patients.

Fundic gland polyps may develop with prolonged use but are generally benign. Rare serious effects include interstitial nephritis, subacute cutaneous lupus erythematosus, and severe skin reactions.

Before starting omeprazole for new-onset dyspepsia in patients over 55, or in the presence of alarm symptoms (unintentional weight loss, dysphagia, haematemesis, persistent vomiting, anaemia), upper gastrointestinal malignancy must be excluded.

Use the lowest effective dose for the shortest necessary duration, particularly in elderly patients.

Monitor magnesium levels during prolonged use, especially in patients also taking digoxin or diuretics.

Omeprazole may reduce the absorption of medications requiring gastric acidity and may increase methotrexate levels.

Losec is contraindicated in patients with known hypersensitivity to omeprazole, substituted benzimidazoles, or any excipient. Co-administration with nelfinavir is contraindicated.

Caution is advised with clopidogrel, as omeprazole may reduce its antiplatelet efficacy; an alternative PPI such as pantoprazole or lansoprazole should be considered.