In vitro performance of cost differentiated ceftriaxone brands against Escherichia coli: insights from a tertiary referral hospital in Mbeya, Tanzania.

Background: In Tanzania, ceftriaxone is one of the most commonly prescribed antibiotics. However, there is quite a significant variation in cost for numerous ceftriaxone brands, leading to the perception that pricier options are more effective. Yet, limited empirical data support this perception.

Methods: Five ceftriaxone brands with a wide price range were tested in vitro against a ceftriaxone-sensitive Escherichia coli clinical isolate using microdilution and spectrophotometry. Brands were evaluated across a spectrum of concentrations. Bacterial growth inhibition was measured using optical density. Analysis of variance was used to compare the bacterial optical densities among the brands.

Results: All brands were comparable at all tested concentrations, with peak inhibition above 1.95 mg/L.

Conclusions: Despite significant price disparities, low-cost and high-cost ceftriaxone brands demonstrated similar in vitro performance against E. coli. This challenges the notion that higher-priced options offer better performance. Further, in vivo studies are recommended to validate these findings.