1. Clinical Overview
Dexlansoprazole is an enantiomer of lansoprazole and a proton pump inhibitor (PPI) that suppresses gastric acid secretion by specific inhibition of the H+/K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. The 60mg strength is a modified-release formulation designed for delayed and prolonged action, making it particularly effective for conditions like erosive esophagitis and non-erosive reflux disease (NERD). It is the first PPI with a Dual Delayed Release (DDR) technology, providing two distinct releases of the drug.
| Onset | Duration | Bioavailability |
|---|---|---|
| Within 1-2 hours for initial acid suppression; maximal effect typically seen after 4-5 days of repeated dosing. | Acid suppression lasts for over 24 hours due to its prolonged plasma concentration profile and extended binding to the proton pump. | Approximately 50-60% when administered orally. Bioavailability is not significantly affected by food. |
2. Mechanism of Action
Dexlansoprazole is a prodrug that is activated in the acidic environment of the parietal cell canaliculus. It is a selective and irreversible inhibitor of the H+/K+ ATPase enzyme (the proton pump), the final common pathway for gastric acid secretion. Its inhibition leads to a profound and long-lasting reduction in both basal and stimulated gastric acid secretion.
3. Indications & Uses
- Healing of all grades of erosive esophagitis (EE)
- Maintenance of healed erosive esophagitis
- Treatment of symptomatic non-erosive gastroesophageal reflux disease (GERD)
4. Dosage & Administration
Adult Dosage: Healing of EE: 60mg once daily for up to 8 weeks. Maintenance of EE: 30mg once daily. Symptomatic GERD (without esophagitis): 30mg once daily for 4 weeks.
Administration: Swallow the capsule whole with a glass of water. Do NOT crush, chew, or split the capsule. Can be taken without regard to food. For patients with swallowing difficulties, the capsule can be opened and the granules sprinkled on one tablespoon of applesauce, swallowed immediately without chewing, and followed with water. Do not store the mixture.
5. Side Effects
Common side effects may include:
- Diarrhea
- Abdominal pain
- Nausea
- Flatulence
- Upper respiratory tract infection
- Vomiting
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Atazanavir | Significantly reduces atazanavir plasma concentration, leading to loss of virologic response. | Major |
| Nelfinavir | Reduces nelfinavir plasma concentration. | Major |
| Rilpivirine | Markedly decreases rilpivirine plasma concentration, increasing risk of resistance. | Contraindicated |
| Clopidogrel | Dexlansoprazole may reduce the antiplatelet effect of clopidogrel (a prodrug activated by CYP2C19). The clinical significance is debated but caution is advised. | Moderate |
| Methotrexate | May increase methotrexate serum levels, potentially leading to toxicity, especially with high-dose methotrexate. | Moderate |
| Warfarin | Potential for increased INR and risk of bleeding due to possible interference with metabolism. Monitor INR closely. | Moderate |
| Ketoconazole, Itraconazole, Posaconazole | Reduced absorption of these drugs due to increased gastric pH, leading to decreased efficacy. | Moderate |
| Digoxin | Increased bioavailability of digoxin due to elevated gastric pH. Monitor digoxin levels. | Moderate |
| Tacrolimus | May increase tacrolimus exposure, especially in CYP2C19 poor metabolizers. Monitor levels. | Moderate |
7. Patient Counselling
- DO swallow the capsule whole with water.
- DO inform your doctor if you are pregnant, planning pregnancy, or breastfeeding.
- DO inform your doctor about all other medicines, vitamins, and herbal supplements you are taking.
- DO take the medicine for the full prescribed duration, even if you feel better.
- DO NOT crush, chew, or split the capsule.
- DO NOT take the medicine if you are allergic to it or similar medicines (like omeprazole, pantoprazole).
8. Toxicology & Storage
Overdose: Expected symptoms would be consistent with the drug's pharmacology and may include confusion, drowsiness, blurred vision, tachycardia, nausea, diaphoresis, flushing, headache, and dry mouth. Doses up to 120mg daily have been administered without reported toxicity.
Storage: Store at room temperature (15°C to 30°C), protected from moisture and light. Keep out of reach of children. Do not use after the expiry date printed on the pack.