What is the treatment for amoebiasis?

Treatment for Amoebiasis

Metronidazole is the first-line treatment for amoebiasis, administered at 750 mg three times daily for 5-10 days for adults, followed by a luminal agent such as paromomycin to prevent relapse. 1

Diagnosis Confirmation

Before initiating treatment, it's important to confirm the diagnosis of amoebiasis:

• Microscopic examination of fresh stool samples to identify Entamoeba histolytica trophozoites
• Consider amoebiasis when patients present with:
  • Dysentery (bloody diarrhea)
  • Abdominal pain
  • History of travel to or residence in endemic areas
  • Failure to respond to treatment for bacterial dysentery

Treatment Algorithm

1. Intestinal Amoebiasis

First-line treatment:

• Adults: Metronidazole 750 mg orally three times daily for 5-10 days 1
• Children: Metronidazole 30 mg/kg/day divided in three doses for 5-10 days 1

Alternative treatment:

• Adults: Tinidazole 2 g daily for 3 days 1, 2
  • Tinidazole may be better tolerated with less nausea than metronidazole 1
  • Studies show tinidazole has higher cure rates (96.5%) compared to metronidazole (55.5%) 3

2. Amoebic Liver Abscess

• Adults: Metronidazole 500 mg three times daily for 7-10 days 1
• Alternative: Tinidazole 2 g daily for 3 days 1
• Most patients will respond within 72-96 hours of treatment initiation 1
• Surgical or percutaneous drainage is rarely required and should only be considered if:
  • Diagnostic uncertainty exists
  • Symptoms persist after 4 days of treatment
  • Risk of imminent rupture, particularly for left-lobe abscesses 1

3. Follow-up Treatment (Critical Step)

After completing treatment with metronidazole or tinidazole, ALL patients should receive a luminal amoebicide to eliminate intestinal cysts and reduce risk of relapse:

• Preferred options:
  • Paromomycin 30 mg/kg/day orally in 3 divided doses for 10 days 1, 4
  • Diloxanide furoate 500 mg orally three times daily for 10 days 1

Important Clinical Considerations

1. Diagnostic pitfalls:

   • Amoebiasis is often misdiagnosed as bacterial dysentery
   • Consider amoebiasis if a patient fails to respond to two different antibiotics for shigellosis 1
   • Serology is particularly useful for diagnosing amoebic liver abscess (>90% sensitivity) 1

2. Treatment efficacy monitoring:

   • Clinical improvement should occur within 72-96 hours
   • If no improvement after 4 days, consider alternative diagnoses or drainage for liver abscess

3. Asymptomatic carriers:

   • Treatment is not recommended for asymptomatic individuals unless microscopic examination confirms the presence of E. histolytica 1
   • Single-agent treatment has poor efficacy in asymptomatic carriers 5

4. Combination therapy:

   • Combined formulations of diloxanide furoate and metronidazole have shown 100% parasitic clearance in clinical studies 6

5. Special populations:

   • For immunocompromised patients, longer treatment courses may be necessary
   • Pregnant women should be treated with appropriate medications after consultation with specialists

Remember that amoebiasis can cause significant morbidity and mortality if left untreated, particularly in cases of invasive disease or liver abscess. Prompt diagnosis and appropriate treatment are essential for optimal outcomes.