In vitro antimicrobial activity of commonly used vasoactive drugs.

Study Objective: Microbial contamination during preparation of the infusion drugs is an important issue in intensive care units. Objective of this study was to investigate in vitro antimicrobial properties of commonly used vasoactive drugs.

Design: Prospective study.

Setting: Clinical microbiology laboratory of a university hospital.

Measurements: Growth of the microorganisms Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans in saline dilutions of adrenaline at 1, 10, and 100 μg/mL; noradrenaline at 1, 10, and 100 μg/mL; and dopamine at 0.1, 1, and 10 mg/mL concentrations was investigated. Each drug solution and saline were analyzed with a digital pH meter.

Main Results: Saline dilutions of adrenaline, noradrenaline, and dopamine at clinically used concentrations decreased microbial growth. The highest concentration doses of adrenaline, noradrenaline, and dopamine used in the study had significant antimicrobial effect when compared to the low and moderate doses. This effect was shown with the all microorganisms. S aureus, S epidermidis, and C albicans were more sensitive; on the other hand, E coli and P aeruginosa were more resistant against the effect of the drug dilutions.

Conclusions: To limit microbial growth in case of contamination of the drug solution, it is advisable to use more concentrated dilutions of adrenaline, noradrenaline, and dopamine used in clinical practice.