Research in context
Evidence before this study
We searched PubMed without language restrictions between Jan 1, 1970, and March 1, 2017, using the search term “tribendimidine” in combination with “opisthorchiasis”, “clonorchiasis”, and “liver fluke”. Previous studies included exploratory clinical trials and dose-finding studies of liver fluke infections. These studies showed promising efficacy for tribendimidine against Opisthorchis viverrini and Clonorchis sinensis. The drug was found to be well tolerated.
Added value of this study
We investigated the efficacy and safety of tribendimidine (single oral dose of 200 mg for children aged 8–14 years and 400 mg for adults and adolescents aged ≥15 years) compared with praziquantel (75 mg/kg bodyweight in two doses) against O viverrini infection. 293 (97·3%) of 301 participants treated with praziquantel and 276 (93·6%) of 295 participants treated with tribendimidine were cured. The difference in cure rates between the groups was −3·8 percentage points (95% CI −7·1 to −0·4). We set our non-inferiority margin at −3 percentage points; thus, non-inferiority for tribendimidine could not be shown because the lower bound of the 95% CI for the difference in cure rates between the groups exceeded this margin. Both treatments resulted in high egg reduction rates (>99%). Participants treated with tribendimidine had significantly fewer and milder adverse events than participants treated with praziquantel. This study is the first direct comparison of the two drugs, showing that tribendimidine has a superior safety profile and similar efficacy to praziquantel.
Implications of all the available evidence
Tribendimidine is a potential candidate to complement praziquantel in the treatment of O viverrini infection. Given that the evidence has come from individuals with light O viverrini infections, further studies are needed in people with moderate and severe liver fluke infections.