The economic impact of once-daily versus conventional administration of gentamicin and tobramycin

This retrospective, observational study was designed to compare once-daily with conventional aminoglycoside administration for costs while determining equivalency in efficacy and toxicity. 100 consecutive patients who had been treated with once-daily aminoglycosides after 1st August 1993, were evaluated via retrospective chart review. For comparison, 100 consecutive patients who were treated with conventional regimens of aminoglycosides, over the same calender period 1 year earlier (beginning on 1st August 1992), were evaluated in a similar manner. Aminoglycoside antibacterials, excluding amikacin, were administered as a single daily dose of 6 mg/kg. 89 patients were cured or improved with once-daily administration versus 90 patients with conventional administration. One patient in each group developed definite aminoglycoside-induced renal toxicity. The total cost [in 1993 Canadian dollars ($Can)] per patient for once-daily and conventionally administered aminoglycosides was $Can97.62 and $ Can199.43, respectively. Thus, once-daily administration of aminoglycosides is as effective and well tolerated, while considerably less expensive than, aminoglycoside treatment utilising conventional regimens.