ECONOMIC-IMPACT OF AMINOGLYCOSIDE TOXICITY AND ITS PREVENTION THROUGHTHERAPEUTIC DRUG-MONITORING

Therapeutic drug monitoring (TDM) of aminoglycoside antibacterials wit h the goal of minimising toxicity and maximising effectiveness has bec ome routine. Successful management of serious infections requires the ability to achieve therapeutic peak concentrations, while maintaining low trough concentrations will assist in avoiding nephrotoxicity. Repo rted nephrotoxicity rates range from 1.7 to 58% and depend on the defi nition used, the patient group studied, concomitant drug therapy used and whether TDM services have been provided. TDM services have been sh own to reduce aminoglycoside nephrotoxicity. The costs of providing TD M averages $US301.87 (1997 values) per patient and the cost for each u se of nephrotoxicity is estimated at $US4583 (1997 values). In order f or the costs of providing a TDM service to 100 patients ($US30 187) to be offset by cost savings due to decreasing nephrotoxicity, the servi ce would need to be able to reduce nephrotoxicity by 6.6%, resulting i n a saving of $US30 248. The ability to achieve this saving is depende nt on the characteristics of the population in which aminoglycoside th erapy is used. In populations where high rates of nephrotoxicity (e.g. >15%) would be expected, TDM services are cost justified. In populati ons where nephrotoxicity is low (e.g. <5%), TDM service is not justifi ed for this purpose. In order to provide a cost-efficient approach to TDM, resources should be focused on providing service to high risk pat ient groups.