A fixed-dose combination antidiarrheal and antiflatulent agent. Loperamide is a synthetic opioid receptor agonist that acts on intestinal μ-opioid receptors to inhibit peristalsis and reduce fluid secretion. Simethicone is an organosilicon polymer that acts as an antifoaming agent, reducing the surface tension of gas bubbles in the GI tract, causing them to coalesce and be expelled more easily.
Adult: Acute Diarrhoea: Initially 2 tablets (4mg Loperamide) followed by 1 tablet (2mg Loperamide) after each loose stool. Maximum: 8 tablets (16mg Loperamide) in 24 hours. Simethicone dose is 125mg per tablet.
Note: Tablets/Capsules should be swallowed whole with water, without chewing. Can be taken with or without food. For acute diarrhoea, maintain adequate fluid intake (ORS) to prevent dehydration.
Loperamide binds to opioid receptors in the myenteric plexus of the large intestine, inhibiting the release of acetylcholine and prostaglandins. This slows intestinal motility, increases transit time, enhances water and electrolyte absorption, and reduces fluid secretion. Simethicone is a surfactant that lowers the surface tension of gas bubbles trapped in GI mucus and food, causing them to coalesce into larger bubbles. This allows gas to be more easily expelled via belching or flatus, relieving pressure and bloating.
Pregnancy: Category C (US FDA). Animal studies show risk. Use only if potential benefit justifies potential risk to the fetus. Not recommended during first trimester. Avoid in late pregnancy as opioid agents may cause neonatal withdrawal.
Driving: May cause dizziness and drowsiness. Patients should not drive or operate machinery until they know how the medicine affects them.
| CYP3A4 Inhibitors (e.g., Ketoconazole, Itraconazole, Ritonavir, Clarithromycin) | Markedly increases Loperamide plasma levels, increasing risk of CNS and cardiac toxicity. | Major |
| CYP2C8 Inhibitors (e.g., Gemfibrozil) | Increases Loperamide levels. | Moderate |
| P-glycoprotein Inhibitors (e.g., Quinidine) | Increases Loperamide penetration into CNS, increasing opioid effects. | Major |
| Other CNS Depressants (e.g., Alcohol, Benzodiazepines, Opioids) | Additive sedative effects. | Moderate |
| Anticholinergic Drugs (e.g., Atropine, Tricyclic Antidepressants) | Increased risk of paralytic ileus and severe constipation. | Moderate |
| Drugs that prolong QT interval (e.g., Erythromycin, Fluoroquinolones, Antipsychotics) | Additive risk of life-threatening cardiac arrhythmias. | Major |
Same composition (Loperamide (2mg) + Simethicone (125mg)), different brands: