Several studies have suggested that irrespective of the mode of action of antibiotics, induction of oxidative stress also contributes to their bactericidal actions. When antioxidants are supplemented with antibiotics, the bactericidal effect of the antibiotic are reduced. Thus, in this study, sensitivity of norfloxacin was analysed in the presence of antioxidants like glutathione and ascorbic acids, then the influence of multivitamins in the sensitivity was also analysed. The effect was studied though disc diffusion, MIC (minimal inhibitory concentration) and DNA damage assays against the model organisms – Pseudomonas aeruginosa and Klebsiella pneumoniae. This study suggested that the antioxidant and vitamin solution were having influence over sensitivity towards the antibiotics whose MIC was determined at highest concentration with reduced zone of inhibition and DNA damage. Hence, these results lead to a hypothetical claim for the involvement of multivitamins / antioxidants to have antibacterial resistance development.