Gentamicin and vancomycin have a narrow therapeutic index i.e. efficacy or the risk of toxicity or treatment failure is related to small changes in concentration of the drugs and hence the accuracy of the dosing. In addition, gentamicin accumulates in the inner ear risking oto-vestibular toxicity if prolonged or recurrent treatment courses. Consequently, accurate prescribing, appropriate therapeutic drug monitoring (TDM) and, in the case of gentamicin, restricted duration of therapy and avoidance of repeat courses are important to minimise risk.
NOTE: Before prescribing these agents ensure you refer to the correct dosing and monitoring guidance and use the correct prescription and monitoring documentation.
Guideline reviewed: June 2021
Page updated: November 2023