Diloxanide Duration After Metronidazole for Entamoeba histolytica
Administer diloxanide furoate 500 mg orally three times daily for 10 days after completing metronidazole treatment for Entamoeba histolytica infection. 1, 2, 3
Why Luminal Therapy Is Mandatory
- All patients who complete metronidazole for amoebic liver abscess or invasive amebiasis must receive a luminal amoebicide to prevent relapse, even when stool microscopy is negative. 1, 2, 3
- Metronidazole alone does not eradicate intestinal cysts; it treats only the invasive tissue form of the parasite. 3
- Omitting luminal therapy leaves patients at risk for recurrent invasive disease from persistent intestinal colonization. 1, 3
Standard Diloxanide Regimen
- Dose: 500 mg orally three times daily 1, 2, 3
- Duration: 10 days 1, 2, 3, 4, 5
- Timing: Begin immediately after completing the 7-10 day course of metronidazole. 1, 2
Alternative Luminal Agent
- Paromomycin 30 mg/kg per day orally in 3 divided doses for 10 days is an alternative if diloxanide is unavailable. 1
Efficacy and Safety Data
- Diloxanide furoate achieves parasitological cure rates of 86-93% in asymptomatic cyst passers when given for the full 10-day course. 4, 5
- The drug is well tolerated, with adverse effects reported in only 14% of treatment courses; most common side effects include flatulence (9%), diarrhea or cramping (4%), and nausea (3%). 5
- Children aged 20 months to 10 years experience fewer adverse effects than adults (3% vs 12%). 5
Critical Practice Points
- Never skip luminal therapy: This is the most common pitfall in managing amebiasis, as clinicians may assume metronidazole alone is sufficient. 1, 3
- Treat even with negative stool studies: Stool microscopy is frequently negative in amoebic liver abscess, but intestinal colonization persists and requires eradication. 1, 2, 3
- Complete the full 10-day course: Shorter courses have not been validated and may result in treatment failure. 1, 4, 5
- Avoid prolonged metronidazole: Do not extend metronidazole beyond 14 days due to cumulative neurotoxicity risk; instead, complete metronidazole and transition to diloxanide. 2, 3