A Case of Alveolar Echinococcosis Treated with Monitoring of Serum Albendazole Concentration

Alveolar echinococcosis associated with systemic metastatic lesions cannot be treated solely by radical resection but also requires long-term oral albendazole (ABZ) therapy. Adverse effects, such as hepatotoxicity and leukopenia, necessitate discontinuation of ABZ treatment in some patients. We report a case of alveolar echinococcosis in which measurement of blood levels of ABZ was useful. A 31-year-old woman was referred to our hospital after multiple biopsies of paravertebral tumors and vertebral arches failed to confirm the diagnosis. Echinococcosis multiforme was diagnosed based on the results of liver biopsy and serum Western blot assay. Treatment was initiated with ABZ 600mg/day; however, the patient developed mild hepatic impairment, and the ABZ dose was reduced to 400mg/day considering the long-term administration schedule. Serum concentrations of ABZ sulfoxide were measured and were at near-optimal levels. The patient experienced no adverse effects to treatment during the one-year follow-up. Measurement of blood ABZ concentrations should be considered to monitor adverse effects, such as hepatic dysfunction, in patients who receive long-term ABZ therapy.