Background: In amebic liver abscess, aalthough metronidazole therapy is very effective in resolving infections; issues of incomplete clearance against intestinal ameba and Drug tolerability remain. Additionally, transmission of metronidazole-refractory amebiasis has been reported. In vitro studies reveal that nitazoaxanide are 1.5 times more active than metronidazole against amebiasis. Till now therapeutic efficacy of nitazoxanide has not been compared with metronidazole in patients with amebic liver abscess.
Material and Methods: This prospective randomized control study recruited 29 patients with uncomplicated amebic liver abscess. 15 patients received metronidazole (800 mg tid. for 10 days) and 14 patients received nitazoxanide (500 mg bid. for 10 days). At 72 hour response to treatment was assessed by resolution of symptoms. In the absence of significant improvement in symptoms, therapeutic aspiration of liver abscess was done. Assessment of treatment response was done 48 hour after needle aspiration. If patients unresponsive to one treatment group at day 5, they were switched to other treatment group and treatment response was assessed after 48 hour.
Results: At day three, 46.6% patients in metronidazole group developed significant clinical improvement whereas none of the patients in nitazoxanide group improved clinically. Therapeutic aspiration of liver abscess was done at day 3. Two days after therapeutic aspiration 93.3% patients in metronidazole group and 42.85% in nitazoxanide group improved clinically. At day 5, metronidazole 800 mg three times per day was started in nitazoxanide unresponsive treatment group. All patients were improved clinically at day 7. Significant correlation of clinical improvement was found with metronidazole therapy, aspiration of liver abscess, and shorter hospital stay.
Conclusion: Nitazoxanide is inferior to metronidazole in treatment of patients with amebic liver abscess. Therapeutic aspiration hastens the rate of symptomatic improvement.