Comparative Cost Effectiveness of Gentamicin and Tobramycin

Abstract

Gentamicin and tobramycin were compared for cost effectiveness in the treatment of adult patients with serious infections in a general medical service. We used data from a randomized double-blind trial in which the only observed difference between the clinical effects of these aminoglycosides was the incidence of nephrotoxicity (26% with gentamicin and 12% with tobramycin). According to 1984 cost data, the combined average drug and nephrotoxicity costs per patient were $127 for tobramycin and $72 for gentamicin. An extensive sensitivity analysis—varying frequency and cost of nephrotoxicity, dialysis requirements, aminoglycoside acquisition costs, and length of hospitalization—showed gentamicin to be more cost effective than tobramycin, unless hospitalization is prolonged by an average of at least 15 days for patients with severe nephrotoxicity or at least 3 days for all patients with moderate or severe nephrotoxicity.