1. Clinical Overview
Racecadotril is an antisecretory antidiarrheal agent, a prodrug of thiorphan, which acts as a potent and selective enkephalinase inhibitor. It is specifically indicated for the symptomatic treatment of acute diarrhea in adults and children. Unlike other antidiarrheals, it reduces hypersecretion of water and electrolytes into the intestinal lumen without affecting intestinal motility, offering a favorable safety profile.
| Onset | Duration | Bioavailability |
|---|---|---|
| Within 30 minutes to 1 hour. | Approximately 6-8 hours. | Approximately 10% (as the active metabolite, thiorphan). |
2. Mechanism of Action
Racecadotril is a prodrug that is rapidly converted to its active metabolite, thiorphan. Thiorphan is a potent and selective inhibitor of membrane-bound enkephalinase (neprilysin). This enzyme is responsible for the degradation of endogenous enkephalins in the gastrointestinal tract. By inhibiting enkephalinase, racecadotril increases the local concentration of enkephalins. Enkephalins then activate delta-opioid receptors on enterocytes, which inhibits adenylate cyclase. This leads to a reduction in intracellular cyclic AMP (cAMP), which in turn decreases the hypersecretion of water and electrolytes into the intestinal lumen.
3. Indications & Uses
- Symptomatic treatment of acute diarrhea in adults.
- Symptomatic treatment of acute diarrhea in children (≥3 months of age).
4. Dosage & Administration
Adult Dosage: 1 sachet (10mg) or 5ml of suspension (10mg) three times daily. Continue for up to 7 days or until the first normal stool, but not more than 7 days.
Administration: Oral administration. The suspension should be shaken well before use. Can be taken with or without food. It is recommended to continue oral rehydration therapy (ORS) concurrently to prevent dehydration.
5. Side Effects
Common side effects may include:
- Headache (mild)
- Nausea
- Constipation (rare compared to loperamide)
- Abdominal pain
- Skin rash
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| ACE Inhibitors (e.g., Enalapril, Ramipril) | Theoretical risk of additive potentiation of endogenous enkephalins; monitor for increased pharmacodynamic effects. | Moderate |
| Diuretics (e.g., Furosemide) | Risk of electrolyte imbalance may be potentiated in dehydrated patients. Ensure adequate rehydration. | Moderate |
| Antihypertensives | Unlikely significant interaction. No clinically relevant pharmacokinetic interactions known. | Minor |
7. Patient Counselling
- DO continue to drink plenty of fluids (ORS, water, clear broths) to prevent dehydration.
- DO take the exact dose as prescribed, based on weight for children.
- DO complete the course even if symptoms improve early, unless advised otherwise.
- DONT use for more than 7 days without consulting a doctor.
- DONT use in case of high fever or blood/mucus in stools without medical advice.
8. Toxicology & Storage
Overdose: No specific symptoms reported from overdose in humans. Based on mechanism, potential symptoms could include severe constipation, nausea, and headache. Significant toxicity is unlikely.
Storage: Store below 30°C. Protect from light and moisture. Keep the bottle tightly closed. Keep out of reach of children. Do not use after the expiry date printed on the label. Once reconstituted (if powder for suspension), the suspension is stable for 7-15 days as per manufacturer's instructions; refer to specific brand leaflet.