Objective: To compare the effects of a combined medication of albendazole (10 mg/kg/day) plus praziquantel (25 mg/kg/day) to those of albendazole alone at different doses (10 and 20 mg/kg/day).
Method: The protoscoleces' viability was studied in a consecutive series of patients affected by intra-abdominal hydatidosis caused by Echinococcus granulosus. In all cases the drugs were given during the month prior to surgery.
Results: A significant increase of patients with nonviable protoscoleces was observed in the group treated with the scolicides combination compared to those treated with albendazole alone, both at a dose of 10 mg/kg/day (P = 0.004) and at a dose of 20 mg/kg/day (P = 0.03). Albendazole sulphoxide levels in serum and in cyst fluid were higher in patients given the combined therapy than in those who received only albendazole (10 mg/kg/day: P = 0.016; 20 mg/kg/day: P = 0.034). Levels in the cysts were not significantly different probably due to the sample size; nevertheless a lineal relation between the values obtained in serum and inside the cysts could be discerned in the patients treated with the combined medication.
Conclusion: Albendazole plus praziquantel is more effective than monotherapy with albendazole in the preoperative treatment of intra-abdominal hydatidosis.