DEVELOPMENT AND IMPLEMENTATION OF SIMPLIFIED AMINOGLYCOSIDE EMPIRIC DOSING GUIDELINES

Poor empiric dosing of aminoglycosides continues to be a problem in ma ny hospitals. Consequently, a two-phase study was undertaken to evalua te gentamicin and tobramycin (G-T) dosing in our institution and to de velop practical guidelines to achieve optimum initial G-T serum concen trations. In the pre-intervention phase (phase 1), approximately one-t hird of 232 G-T treatment courses were initiated with regimens that re sulted in low initial serum concentrations. Empiric dosing guidelines were subsequently developed using Pharmacy Pharmacokinetic Service dat a and literature recommendations. They were validated with patients in phase 1. Compared with earlier dosing methods, the guidelines resulte d in initial serum G-T concentrations within the therapeutic range in an equivalent proportion of patients. To simplify the procedure, recom mended dosages were based on age, total weight, and serum creatinine o nly. The guidelines were tabular in format, and prescriber calculation s were not required. Pocket and wall chart guidelines were distributed and promoted. During the post-intervention phase (phase 2), the impac t of the guidelines was assessed. A review of 232 phase 1 and 203 phas e 2 treatment courses revealed an increase in the initial mean dose pe r interval prescribed after the intervention (p<0.01). No change in th e mean interval was noted. When guidelines were followed, a higher pro portion of treatment courses achieved early therapeutic serum concentr ations (CP(max) 5-10 mg/L, 80% vs 54%; p<0.005). The new empiric guide lines appear to be a practical alternative to existing methods of dosi ng aminoglycosides.