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The preventive effect of diphenhydramine on bacterial growth in propofol: a laboratory study
A Güzelant1, S Apiliogullari, I Kara
1Meram Teaching & Research Hospital, Department of Microbiology, Konya, Turkey.
Background And Objective:
Diphenhydramine has local anaesthetic and antimicrobial activity and may be used to prevent intravenous propofol injection pain. We studied the effect of adding diphenhydramine to propofol emulsions for preventing bacterial growth.
Methods:
Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans cultures were inoculated into the following solutions: 1% propofol, 0.05% diphenhydramine + 1% propofol, 0.1% diphenhydramine + 1% propofol, 0.2% diphenhydramine + 1% propofol, 0.3% diphenhydramine + 1% propofol, 1% diphenhydramine and 0.1% lidocaine + 1% propofol. A 100-microL of inoculum suspension adjusted for each of the micro-organisms was added separately to each tube and left at 20 degrees C. A 10-microL aliquot of each mixture was inoculated onto blood agar medium at 5 and 24 h. These plates were incubated at 35 degrees C for 24 h. Each plated medium was read, and the number of colony-forming units were counted and recorded (n = 2). Analysis of variance (ANOVA) with a post hoc Tukey HSD test and paired t-tests were used for data analysis. P < 0.05 was considered as significant.
Results:
Diphenhydramine inhibited bacterial growth in propofol solutions in a dose-dependent manner. It was more effective than 0.1% lidocaine at similar concentrations in preventing bacterial growth for all organisms.
Conclusion:
Diphenhydramine had a significant inhibitory effect on bacterial growth in propofol.
Insights
Diphenhydramine effectively inhibits bacterial growth in propofol emulsions, offering a potential solution for preventing microbial contamination. This antimicrobial activity was observed in a dose-dependent manner across various microorganisms.
Area of Science:
- Microbiology
- Pharmacology
- Anesthesiology
Background:
- Diphenhydramine exhibits local anesthetic and antimicrobial properties.
- It is considered for mitigating propofol injection pain.
- The study investigates its role in preventing bacterial contamination in propofol.
Purpose of the Study:
- To evaluate the antimicrobial efficacy of diphenhydramine when combined with propofol.
- To determine if diphenhydramine prevents bacterial growth in propofol emulsions.
- To compare diphenhydramine's effectiveness against common microorganisms with lidocaine.
Main Methods:
- Cultures of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans were exposed to varying concentrations of diphenhydramine in 1% propofol.
- Microbial growth was assessed at 5 and 24 hours post-inoculation.
- Statistical analysis included ANOVA and paired t-tests to determine significance (P < 0.05).
Main Results:
- Diphenhydramine demonstrated a dose-dependent inhibition of bacterial growth in propofol solutions.
- Its antimicrobial effect was superior to 0.1% lidocaine at comparable concentrations.
- All tested organisms showed reduced growth in the presence of diphenhydramine.
Conclusions:
- Diphenhydramine possesses significant antimicrobial properties against bacteria in propofol emulsions.
- The findings support diphenhydramine's potential as an additive to propofol to prevent microbial contamination.
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