A fixed-dose combination (FDC) antiprotozoal and antibacterial agent primarily used for the treatment of intestinal amebiasis and giardiasis. Metronidazole is a nitroimidazole antibiotic effective against anaerobic bacteria and protozoa, while Diloxanide furoate is a luminal amebicide that acts directly on trophozoites in the intestinal lumen. This combination provides a synergistic effect for eradicating both luminal and systemic forms of Entamoeba histolytica.
Adult: 1 tablet (Metronidazole 100mg + Diloxanide 125mg) three times daily for 5-10 days. For acute amebic dysentery: Typically 10 days.
Note: Take with or after food to minimize gastrointestinal upset. Swallow whole with a full glass of water. Complete the full prescribed course even if symptoms improve earlier.
Metronidazole enters microbial cells and is reduced by nitroreductase enzymes in anaerobic bacteria and protozoa. This reduction forms cytotoxic nitro radical anions that damage microbial DNA, leading to strand breakage and inhibition of nucleic acid synthesis. Diloxanide furoate is hydrolyzed in the intestinal lumen to Diloxanide and furoic acid. Diloxanide acts directly on trophozoites of Entamoeba histolytica, likely by disrupting protein synthesis and microtubule function, but its exact mechanism is not fully elucidated. The combination targets both invasive (Metronidazole) and luminal (Diloxanide) forms of the parasite.
Pregnancy: Category B (US FDA) for Metronidazole, but Category C in some classifications. Diloxanide furoate: Human data insufficient. Generally contraindicated in the first trimester. Use in second/third trimester only if potential benefit justifies potential fetal risk. Avoid high-dose or prolonged therapy.
Driving: May cause dizziness, vertigo, ataxia, or confusion. Patients should be cautioned about driving or operating machinery until their response is known.
| Alcohol | Disulfiram-like reaction (flushing, headache, nausea, vomiting, tachycardia) | Major |
| Warfarin | Metronidazole inhibits warfarin metabolism (CYP2C9), increasing INR and risk of bleeding | Major |
| Lithium | Metronidazole may increase lithium levels, risk of toxicity | Moderate |
| Phenobarbital/Phenytoin | May increase metabolism of Metronidazole, reducing its efficacy | Moderate |
| Cimetidine | May decrease metabolism of Metronidazole, increasing its levels and toxicity risk | Moderate |
| 5-Fluorouracil | Metronidazole may reduce clearance, increasing toxicity | Moderate |
Same composition (Metronidazole (100mg) + Diloxanide (125mg)), different brands: