Paromomycin therapy of endemic amebiasis in homosexual men

Efficacy and safety of paromomycin for treating amebiasis in Japan

The clinical management of amebiasis is a growing concern, particularly among human immunodeficiency virus (HIV)-infected individuals who are predisposed to severe illness. Treatment with a luminal amebicide is strongly recommended following acute-stage treatment with a nitroimidazole. In 2004, the Japanese Research Group on Chemotherapy of Tropical Diseases introduced paromomycin, which was not nationally licensed, and offered it to a number of patients. From 2004 to 2011, 143 case records of amebiasis (123 with amebic colitis, 16 with amebic liver abscess, and 4 with both) in which patients were treated with paromomycin, mainly 1,500 mg/day for 9 or 10 days following metronidazole treatment, were submitted. Among 123 evaluable cases, 23 (18.7%) experienced possible adverse effects, the most common being diarrhea (17/123, 13.8%) and other gastrointestinal problems that were resolved after the completion or discontinuation of treatment. In addition, single cases of bloody stools associated with Clostridium difficile colitis, skin rash, and the elevation of liver enzymes were also reported, although the causal relationship was not clear. HIV infection did not appear to increase the incidence of adverse drug effects. Each of the 11 asymptomatic or mildly symptomatic amebic colitis cases became negative for stool cysts after paromomycin treatment. Paromomycin was shown to be safe and well tolerated, as well as effective in a special subset of amebic colitis cases.

Human antiprotozoal therapy: past, present, and future

Human protozoal infections are ubiquitous and occur worldwide. In many cases, antiprotozoal agents currently in use predate the modern antibiotic era. Despite the relative lag in development of new antiprotozoal agents, the 1990s have witnessed an increasing level of interest in these infections, inspired by international travel and immigration, a growing awareness of antiprotozoal drug resistance, and the significance of acute and recrudescent protozoal infections in immunosuppressed hosts. This review summarizes for nonclinician readers the past, present, and future therapies for common human protozoal infections, as well as pharmacologic mechanisms of action and resistance and common toxicities associated with these agents.