Carbapenems are antibiotics of the cephalosporin family with a good penetrance into the central nervous system. Neurotoxicity is a rare adverse effect, most often associated with imipenem (0.4-10 %) and unusual with ertapenem. It usually presents as seizures, although encephalopathy or hallucinations may develop. However, a recent large study (n = 544) found neurotoxicity associated to the use of ertapenem with an incidence of 4.6 %. There were associated factors such as advanced age or renal dysfunction (ertapenem has a renal metabolism level of 80 %).