Since 2017 the world suffers from a piperacillin/tazobactam shortage. Cefepime is then proposed as a broad spectrum antibiotic alternative. Up to 15 % of the patients under treatment develop neurotoxicity, mostly in kidney failure settings. Cefepime serum concentration and electroencephalogram guide diagnosis. Treatment consists in withholding or reducing the dose. Most of the patients recover without neurologic sequelae.