Treatment of Scabies among Elderly Japanese Patients Using Ivermectin and γ–Benzene Hexachloride

Background: Oral ivermectin is currently recommended for treating scabies. We determined whether ivermectin is effective and safe for the treatment of scabies in elderly patients. Subjects and methods: Ivermectin(200 μg/kg) was administered once and then again at two–week intervals if required to 44 elderly patients with clinical and microscopic evidence of infestation with live Sarcoptes scabiei mites. Those with mites in nail plates were treated with vaseline ointment followed by ivermectin and topical γ–benzene hexachloride at ≳ 4–day intervals. Patients were monitored by routine blood biochemical analysis, liver and kidney function tests, urinalysis and abdominal ultrasonography. Results: The cure rates of one, two and three doses of ivermectin were 20%, 65% and 15%, respectively. Two patients who received topical γ–benzene hexachloride after ivermectin were cured at four weeks. Liver dysfunction that might have been an adverse reaction to ivermectin developed in one 85 – year–old male patient. Urea nitrogen levels that slightly increased in three patients returned to normal after withdrawing ivermectin. Serum creatinine was not affected. Conclusions: Ivermectin appears to be a safe option for treating scabies in elderly Japanese, but liver function requires careful monitoring for adverse reactions.