Therapeutic drug monitoring of antimicrobials


  • Jason A. Roberts,

    Corresponding author
    1. Burns, Trauma and Critical Care Research Centre
    2. Department of Intensive Care
    3. Pharmacy Department
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  • Ross Norris,

    1. School of Pharmacy
    2. Australian Centre for Paediatric Pharmacokinetics, Mater Pharmacy Services, Brisbane, Queensland, Australia
    3. School of Pharmacy, Griffith University, Gold Coast, Queensland, Australia
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  • David L. Paterson,

    1. Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
    2. Department of Infectious Diseases, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
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  • Jennifer H. Martin

    1. The University of Queensland School of Medicine Southside, Princess Alexandra Hospital, Woolloongabba, Brisbane, Queensland, Australia
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Dr Jason Roberts, Burns Trauma and Critical Care Research Centre, The University of Queensland, Level 3 Ned Hanlon Building, Royal Brisbane and Women's Hospital, Butterfield Street, Brisbane, Queensland 4029, Australia. Tel.: +61 7 3636 4108. Fax: +61 7 3636 3542. E-mail:


Optimizing the prescription of antimicrobials is required to improve clinical outcome from infections and to reduce the development of antimicrobial resistance. One such method to improve antimicrobial dosing in individual patients is through application of therapeutic drug monitoring (TDM). The aim of this manuscript is to review the place of TDM in the dosing of antimicrobial agents, specifically the importance of pharmacokinetics (PK) and pharmacodynamics (PD) to define the antimicrobial exposures necessary for maximizing killing or inhibition of bacterial growth. In this context, there are robust data for some antimicrobials, including the ratio of a PK parameter (e.g. peak concentration) to the minimal inhibitory concentration of the bacteria associated with maximal antimicrobial effect. Blood sampling of an individual patient can then further define the relevant PK parameter value in that patient and, if necessary, antimicrobial dosing can be adjusted to enable achievement of the target PK/PD ratio. To date, the clinical outcome benefits of a systematic TDM programme for antimicrobials have only been demonstrated for aminoglycosides, although the decreasing susceptibility of bacteria to available antimicrobials and the increasing costs of pharmaceuticals, as well as emerging data on pharmacokinetic variability, suggest that benefits are likely.