Background: Oxybutynin is a tertiary amine and has chemical similarities like protamine sulfate. Protamine sulfate's effect on bacterial viability has been shown in some studies; however, there is scanty data regarding the effect of oxybutynin on bacterial viability. Accordingly, the aim of the present study was to investigate the effect of oxybutynin on bacterial viability.
Methods: Twenty of Staphylococcus epidermidis (S. epidermidis) strains were isolated from patients who had catheter-associated urinary tract infection. These strains were exposed to 5 different concentrations of oxybutynin in tryptic soy broth (TSB) media (max: 5 mg/mL, min: 0.05 mg/mL). Quantitative growth patterns were measured by spectrophotometer. Under the same media conditions, biofilm production of individual strains was measured by Deighton's micromethod at the end of the 6-hour incubation period.
Results: After the incubation period, weak and strong slime-producing bacteria groups were obtained and both groups' slime productions were extensively low at 5 mg/mL concentration of oxybutynin. Slime production of S. epidermidis was inversely correlated with oxybutynin concentrations.
Conclusion: Although there was a dose-dependent reduction of biofilm production, there seemed to be no bactericidal effect of oxybutynin on S. epidermidis.