Ropivacaine is a commonly used local anaesthetic, but its side effects remain largely unknown. In the present study, we investigated the side effects of ropivacaine in human neuronal SH-5Y5Y cells. We show that 0.5% and 1% ropivacaine could cause fission-like mitochondrial morphological changes. Ropivacaine exclusively induces mitochondrial fission protein DRP1, generation of ROS and causes mitochondrial dysfunction including decreasing mitochondrial membrane potential, the activity of cytochrome C oxidase and ATP production. The side effects of...