Praziquantel in human hydatidosis. Evaluation by preoperative treatment

The efficacy of praziquantel has been studied in human hydatic disease due to E. granulosus, using parasitological and pharmacological criteria of improvement. This evaluation uses a prospective therapeutic trial in 15 patients with one or several hydatic cysts in different sites. Before surgery, nine of these received daily 75 mg/kg of praziquantel in 2 courses of 10 days each. The other six patients are considered as controls. The protoscolices vitality is determined by direct optic microscopy and by intraperitoneal mouse inoculation. According to the results of optic microscopy, praziquantel sterilizes hydatic cysts: 19 sterilized cysts out of 26 coming from treated patients, and 4 out of 11 in control group. This effect seems to be emphasized in hepatic localization. Nevertheless, according to the results of mouse inoculation, praziquantel does not significantly reduce the pathogenicity of inoculated proscolices and germinal layer: 11 mice out of 39 are healthy in the treated group, and 5 out of 15 in controls. Moreover, the determination with a fluorimetric method has not detected praziquantel in the hydatid liquid issued from treated patients. The drug does not pass through the cyst wall, and so, cannot have a scolicidal activity. Praziquantel cannot be considered as a medical treatment in human hydatidosis.