LANSPURE 15

Indications

• Gastroesophageal reflux disease (GERD)
• Erosive esophagitis associated with GERD
• Symptomatic treatment of heartburn

Dosage

Children: For children aged 12 years and older, the recommended dose is 30 mg once daily. For children aged 1 to 11 years, dosing should be based on weight and should refer to the BNF for Children for specific guidance.

Adults: The usual dose for adults is 60 mg once daily, taken at least 30 minutes before a meal.

Mechanism of action

Dexlansoprazole suppresses gastric acid secretion by inhibiting the H/K ATPase enzyme at the secretory surface of gastric parietal cells. This enzyme is crucial for the secretion of hydrochloric acid, as it hydrolyzes ATP and exchanges H+ ions for K+ ions, leading to acid secretion into the gastric lumen.

Pharmacodynamics

As a proton pump inhibitor, dexlansoprazole effectively suppresses both basal and stimulated gastric acid secretion. However, it is associated with potential rebound acid hypersecretion upon discontinuation. Long-term use raises concerns regarding increased risks of bacterial infections, deficiencies in vitamin B12 and iron, hypomagnesemia, and potential links to osteoporosis and bone fractures. It may also interfere with certain diagnostic tests, such as the secretin stimulation test and urine screening for tetrahydrocannabinol.

Pharmacokinetics

Dexlansoprazole is absorbed in the gastrointestinal tract, with its peak plasma concentration typically occurring within 1 to 3 hours after administration. It undergoes extensive hepatic metabolism, primarily through the cytochrome P450 system. The drug has a half-life of approximately 1 to 2 hours, but its effects on acid secretion can last much longer due to the irreversible nature of proton pump inhibition. It is excreted mainly via urine and feces.

Contra-indications

• Hypersensitivity to dexlansoprazole or any component of the formulation
• Concomitant use with rilpivirine-containing products

Adverse effects

• Headache
• Diarrhea
• Nausea
• Abdominal pain
• Flatulence
• Constipation
• Dizziness
• Fatigue
• Rash
• Elevated liver enzymes
• Kidney injury
• Clostridium difficile infection in the colon

Interactions

• May reduce the effectiveness of clopidogrel due to CYP2C19 inhibition
• Increased levels of drugs that are pH-dependent for absorption (e.g., ketoconazole)
• May interact with methotrexate
• Potential interaction with warfarin leading to increased INR

Precautions

• Use with caution in patients with hepatic impairment
• Long-term use may increase the risk of gastrointestinal infections
• Monitor magnesium levels in patients on prolonged therapy
• Risk of bone fractures in patients with long-term use
• Consider monitoring vitamin B12 levels with long-term use

Pregnancy

Animal studies have not shown teratogenic effects; therefore, it should be used during pregnancy only if clearly needed.

Breast-feeding

It is not known whether dexlansoprazole is excreted in human milk; caution should be exercised when administering to breastfeeding women.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Capsules for oral use (30 mg, 60 mg)

Mechanism of action

Dexlansoprazole suppresses gastric acid secretion by blocking the final step of acid production. It inhibits the H/K ATPase at the secretory surface of the gastric parietal cell, which is involved in the secretion of hydrochloric acid. H/K ATPase is a proton pump responsible for hydrolyzing ATP and exchanging H⁺ ions from the cytoplasm for K⁺ ions in the secretory canaliculus: this action results in hydrochloric acid secretion into the gastric lumen.

Pharmacodynamics

Dexlansoprazole is a proton pump inhibitor (PPI) that suppresses both basal and stimulated gastric acid secretion. PPIs are associated with a risk for a rebound effect and a short-term increase in hypersecretion; thus, such risk cannot be excluded with dexlansoprazole. With long-term use, PPIs are also associated with a risk of increased susceptibility to bacterial infections, vitamin B12 and iron deficiency, and hypomagnesemia and hypocalcemia, possibly leading to osteoporosis and bone fractures. Dexlansoprazole is reported to interfere with the secretin stimulation test and create false positive urine screening tests for tetrahydrocannabinol. Dexlansoprazole can increase gastrin levels, which can cause enterochromaffin-like cell hyperplasia and increase serum CgA levels. Increased CgA levels may cause false positive results in diagnostic investigations for neuroendocrine tumours.