A sustained release antimicrobial cannula or catheter for residence within a portion of a human body through which aqueous biological fluids can pass. The antimicrobial cannula for catheter including a tube having an inner surface, defining and interior lumen, and an outer surface. The tube has a polymeric matrix and an antimicrobial agent residing within at least a portion of the polymeric matrix. The polymeric matrix includes cured silicon rubber and the antimicrobial agent is a finely divided nitrofuran compound, a paraben antifungal, or combinations thereof, which is soluble in water and effective to prevent proliferation of certain microbes in an otherwise growth supporting aqueous environment when dissolved in the aqueous environment to the limit of its solubility therein at 37°C. The solubility of the antimicrobial agent is for example about 0.5% by weight or less at a pH of about 6 and a temperature of about 25°C. The antimicrobial agent can diffuse out of the polymeric matrix and into an aqueous biological environment when the polymeric matrix comes into contact with such an aqueous biological environment. In an embodiment, at least a finite portion of the polymeric matrix proximate the outer surface includes an amount of from about 10 to about 60% by weight of the antimicrobial agent and the amount of the antimicrobial agent and the solubility thereof cooperate to provide a potential for a sustained release diffusion thereof for a period of not less than about three weeks during normal use of the cannula within the human body. Methods of making a sustained release antimicrobial cannula and of catheterizing a patient are also disclosed.Linvention concerne une canule ou un cathéter antimicrobien à libération prolongé destiné à rester à lintérieur dune portion dun corps humain, à travers lequel des fluides biologiques aqueux peuvent passer. La canule ou le cathéter antimicrobien comprend un tube ayant une surface interne, définissant une lumière interne, et u
