A comparison study of two treatment regimens of praziquantel in patients with opisthorchiasis: a randomized trial

BACKGROUND: Opisthorchis viverrini (OV) infection is shown to be related with cholangiocarcinoma. There are several treatment regimens for OV infection including the Cholangiocarcinoma Screening and Care Program (CASCAP) regimen and the Department of Disease Control (DDC) regimen. There is limited data on the cure rate of both regimens. This study aimed to investigate if the CASCAP and DDC praziquantel treatment regimens are comparable or not. METHODS: This study was a randomized, open -labelled trial with an active comparator. The inclusion criteria were adult patients with an age of 15 years or over who registered in the community cohort, had positive test for OV by urine OV-RDT, and agreed to receive a treatment with praziquantel. Eligible patients were randomly assigned to either CASCAP or DDC regimen. The primary outcome of the study was cured rate in both groups defined by negative urine OV-RDT test at 6 weeks after praziquantel treatment. RESULTS: There were 1525 patients participated in the study and categorized as CASCAP group (774 patients) and DDC group (751 patients). The cure rates of both groups were comparable (86.69% in CASCAP group and 87.62% in DDC group; P=0.590). The cure rates were also comparable in a subgroup analysis by weight of less than 65 kg and 65 kg or over (P=0.608 and P=0.791, respectively). Over half of patients reported mild side effects (53.49% in CASCAP group and 53.90% in DDC group; P=0.562). CONCLUSIONS: Both CASCAP and DDC regimens are comparable for OV treatment in a community setting with modest cure rate and mild side effects of praziquantel.