Matthew Falagas and Drosos Karageorgopoulos of the Alfa Institute of Biomedical Sciences in Athens, Greece, argue that dosing by weight would maximise treatment effectiveness.
Increasingly levels of obesity mean that overweight patients whose doses need adjusting can longer be deemed to be special cases, they said.
But, they warn in their Lancet viewpoint piece that, even with computer algorithms, calculating doses will involve time and effort and could make dosing errors more common.
'We believe that the one-size-fits-all strategy for prescribing antimicrobial agents to adults is outdated in the era of increasing antimicrobial drug resistance,' they said.
The individual body size and composition characteristics of patients could substantially affect pharmacokinetic indices and clinical effectiveness of several antimicrobial agents, they point out.
'Appropriate studies are needed to provide guidance to clinicians on the common clinical question of how to achieve optimum effectiveness and safety of antimicrobial therapy for patients whose physical characteristics deviate from average.'