Five patients developed amebic abscess from one to three months after apparent successful treatment of amebic colitis with metronidazole. This observation suggests that metronidazole, although a highly effective amebicide, should not be used as the single agent in therapy of amebic colitis.
David M. Weber. Amebic Abscess of Liver Following Metronidazole Therapy. JAMA. 1971;216(8):1339–1340. doi:10.1001/jama.1971.03180340059016