Long-term evaluation of patients with hydatidosis treated with benzimidazole carbamates.

Four hundred forty-eight patients with 929 Echinococcus granulosus hydatid cysts received 3- to 6-month continuous cycles of mebendazole or albendazole treatment and underwent prolonged follow-up by clinical visits and imaging studies (range, 1-14 years) to assess the long-term outcome of treatment. Degenerative changes and relapse were assessed by imaging techniques. At the end of therapy, 74.1% of the hydatid cysts showed degenerative changes. These were more frequent in albendazole-treated than in mebendazole-treated cysts (82.2% vs. 56.1%; P < .001). During long-term follow-up, 104 cysts (22%) had degenerative changes that progressed, whereas 163 cysts (approximately 25%) relapsed. The percentages of relapses in the two drug-treated groups were almost the same. Relapses occurred more frequently in type II cysts of the liver. Cysts recurred most often (78.5%; P < .001) within the first 2 years after treatment ended. Further chemotherapy cycles induced degenerative changes in >90% of relapsed cysts without inducing more frequent or more severe side effects than those observed during the initial cycles.