Clinical evaluation of the therapeutic efficacy of praziquantel (Embay 8440) against Clonorchis sinensis infection in man

Abstract

A total of 63 patients with proven Clonorchis sinensis infection were treated with praziquantel at two dose levels: 35 patients received 3×25·0 mg/kg body weight (bwt) on a single day, and 28 patients were treated with a single dose of 40·0 mg/kg bwt. Follow-up examinations were carried out at about 30 and 60 days after treatment. Where eggs were found at the first or second follow-up examination, patients were treated again with the same dosage of praziquantel and the follow-up continued for another 60 days. Two months after therapy 30 of 35 patients treated with 3×25·0 mg/kg bwt were parasitologically cured. Five patients received the dosage of 3×25·0 mg/kg bwt for a second time and were also cured. After a single dose of 40·0 mg/kg bwt, only seven of 28 patients were cured at 60 days after therapy. Twenty-one patients received 40·0 mg/kg bwt once for a second time and seven of these 21 patients were cured. The remaining 14 patients showed egg reduction rates in excess of 90%. Extended haematological and biochemical tests, and urinalysis, revealed no abnormal findings which could be related to the compound after therapy. The anthelmintic was well tolerated, there being few untoward side effects, these consisting particularly of mild and transient headache and dizziness. There was no great difference between the two dosage groups. The results obtained in this study suggest that praziquantel may become the drug of choice for the treatment of human clonorchiasis, including its use for large scale community health projects.