A Case Report: Ertapenem-Induced Encephalopathy.

We present a 46-year-old patient who developed acute psychotic and neurological symptoms associated with the use of intravenous ertapenem, a carbapenem antibiotic. He was hospitalized following a road traffic accident where he sustained an open fracture over the right lower limb requiring intravenous antibiotics. He started to exhibit hallucinations, odd beliefs and twitching movements two weeks after the initiation of ertapenem. Other organic causes for this acute change in behaviour were ruled out. His symptoms continued despite the use of antipsychotics but quickly resolved within three days of the withdrawal of ertapenem. Antibiotic-induced encephalopathy, which can manifest as neurological or psychiatric symptoms, is uncommon but clinically significant. Among these, carbapenems have been occasionally associated with encephalopathy through GABAergic inhibition. This case highlights the importance of recognizing ertapenem-induced neuropsychiatric complications even in patients without conventional risk factors, underscoring the need for vigilance when evaluating acute behavioural changes during antibiotic therapy.