Ureteral catheters are indispensable devices used in the management of ureteral obstruction. Although the stent is essential for treatment, it also has complications, which are encrustation, stone formation and biofilm formation. Biofilm infections result in a complication in the course of treatment, increasing the length of patients stay in hospital and overall cost. Catheter-associated infections are difficult to be treated with antibiotics and there is a need to change catheters due to the formation of biofilm on their surfaces. In this study, In this study, we examine the effect of some of prescribed drugs as NSAIDs and N-acetylcysteine on the adherence of S. aureus, K. pneumoniae, P. aeruginosa and Proteus mirabilis on the surface of catheters, and their effects on the preformed mature biofims. Also, we determine their antibacterial activity. The results showed that the tested agents had good antibacterial activity, a significant effect on the inhibition of adherence of the tested strains to plastic surfaces and a high disruptive effect on mature biofilms. In conclusion, the tested drugs can be used in the treatment of catheterassociated infections.