Table 1.

Maximum concentrations for commonly used for beta-lactam drugs.

Drug	Maximum Unbound Trough Concentration	Toxicity with Reported Associated with Supratherapeutic Concentration
Flucloxacillin	20 mg/L	neurotoxicity [75] *
Cefepime	20 mg/L	neurotoxicity [100]
Piperacillin	130 mg/L	neurotoxicity, nephrotoxicity [74]
Meropenem	44 mg/L	neurotoxicity, nephrotoxicity [74]

* Based on expert opinion; concentrations above 20 mg/L are more than 10 times above the EUCAST ECOFF for oxacillin.