Shelf Life of Gentamicin IV
Gentamicin IV solutions prepared for clinical use can be stored refrigerated at 4°C for up to 4 weeks without loss of antibiotic concentration, bactericidal activity, or stability when diluted in normal saline with heparin. 1
Storage and Stability Data
Refrigerated storage at 4°C maintains gentamicin stability for 4 weeks, with mean concentration remaining at 86 ± 3 mcg/mL (starting from 100 mcg/mL) and bactericidal activity stable at 1:242 ± 22 titer throughout the storage period. 1
Bactericidal efficacy against both methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa remains unchanged over the 4-week refrigerated storage period when gentamicin is diluted in heparin/saline solution. 1
Clinical Context
While the research evidence demonstrates 4-week stability under refrigerated conditions for prepared solutions 1, this applies specifically to antibiotic-lock technique preparations at 100 mcg/mL concentration in normal saline with heparin.
For standard IV gentamicin preparations used in clinical practice:
Manufacturer-supplied vials typically have expiration dates of 2-3 years when stored at room temperature in unopened containers, though specific shelf life varies by manufacturer and formulation.
Once diluted for IV administration, gentamicin solutions should generally be used within 24 hours at room temperature or 48-72 hours if refrigerated, following standard institutional pharmacy guidelines for IV admixtures.
Multidose vials once opened should not exceed the number of doses specified in package inserts (e.g., 10 doses for Fluzone, 20 doses for Afluria), with residual product discarded. 2
Important Considerations
The 4-week stability data 1 represents research conditions with specific concentrations and storage parameters, not standard clinical IV preparations.
Always verify manufacturer-specific expiration dating on unopened vials and follow institutional pharmacy policies for prepared IV solutions.
Gentamicin concentration and bactericidal activity remain stable when properly stored, but institutional infection control policies may mandate shorter use periods for opened or diluted preparations.