Comparison of metronidazole and chloroquine for the treatment of amoebic liver abscess. A controlled trial.
Chloroquine and metronidazole were compared in a randomized trial for the treatment of amoebic liver abscess in 36 patients. An additional 30 patients were treated without randomization. Chloroquine was given according to the standard protocol at Los tangeles County-University of Southern California Medical Center, which is 500 mg daily for 10 weeks, whereas metronidazole was given in a dose of 750 mg three times daily for 10 days. Criteria for the diagnosis of amoebic abscess included (a) a suitable clinical picture, (b) filling defect on hepatic scan, (c) high titer of antibody to Entamoeba histolytica by indirect hemagglutination, and (d) eventual complete recovery with treatment or appropriate findings on autopsy examination. Treatment failure, defined as illness that persisted beyond 10 days or recurred after that time, occurred in 1 of 28 patients treated with chloroquine and in 2 of 36 treated with metronidazole. In 2 patients who died it was difficult to assess the result of drug therapy. We conclude that both drugs are highly effective. Metronidazole has the advantage of effectiveness against intestinal amoebiasis and the probability of cure with a shorter course of treatment. Speed of response was slightly greater with metronidazole and was somewhat related to abscess size.