The types and timing of the degenerative changes seen in the cysts during and after benzimidazole treatment of cystic echinococcosis.

AbstractIn a large-scale Bulgarian study, 122 patients with abdominal and/or lung echinococcosis were randomly selected for treatment with albendazole or mebendazole. The main aims were to evaluate the effect of each drug on the hydatid cysts, to follow the changes in cyst morphology during and after treatment, and to determine how quickly each drug produced the first, detectable, degenerative changes in the cysts. Follow-up was based on periodic ultrasonography, chest radiography and computed tomography. The abdominal cysts were categorised as small (<5 cm in diameter) or large. As albendazole treatment had effects that were almost identical to those of mebendazole treatment, the results for the two drugs were combined. In the lungs and, particularly, in the abdomen, the size of the cysts being treated influenced the character and timing of the degenerative changes seen in them.The initial change seen in each abdominal cyst was detachment of the endocyst, which occurred 1–3 months (small cysts) or 2–5 mo...