Continuous linezolid infusion: the new way to dose, the old risks to fear.

Continuous infusion (CI) of linezolid has been proposed to stabilize exposure and improve pharmacokinetic/pharmacodynamic (PK/PD) target attainment compared with conventional intermittent dosing. By maintaining concentrations above inhibitory thresholds, CI may optimize antibacterial efficacy and reduce inter- and intra-patient variability. However, this 'new way of dosing' revisits 'old risks' associated with linezolid, including nonlinear PK, metabolic saturation, and concentration-dependent toxicities such as lactic acidosis, myelosuppression and neurotoxicity. Rather than eliminating these concerns, CI may accentuate them by prolonging exposure near toxic thresholds, particularly in patients with impaired elimination. Current evidence is predominantly PK; robust clinical outcome data remain limited. Our review synthesizes pharmacometric, observational and trial data and outlines how therapeutic drug monitoring and model-informed precision dosing can be used to individualize CI while surveilling for toxicity. We propose a pragmatic framework for candidate selection, regimen design aligned to PK/PD goals, early therapeutic drug monitoring with adaptive adjustments and vigilant safety monitoring. Overall, CI of linezolid is mechanistically attractive but is not established as standard of care; its use should remain individualized, safety-conscious and evidence-generating pending randomized controlled trials.