A method for imparting broad spectrum antimicrobial activity to a medical device. The medical device is sequentially contacted with a first antimicrobial component, such as an antiseptic, and thereafter with a second antimicrobial component, such as a mixture of antibiotics. The first component may be a guanidium compound, such as chlorhexidine. The second component may be a mixture of a tetracycline, such as minocycline, and a rifamycin, such as rifampin.