To compare the safety and the efficacy of tigecycline to vancomycin with aztreonam in treating hospitalized patients with complicated skin and/or skin structure infections.

Inclusion Criteria:

• Anticipated need for intravenous antibiotic therapy of 5 days or longer.
• Patients known or suspected to have a complicated skin and skin structure infection. Complicated skin/skin structure infection includes infections either involving deeper soft tissue or requiring significant surgical intervention or a significant underlying disease state (such as diabetes mellitus, peripheral vascular disease, peripheral neuropathy, lower venous insufficiency) that complicates response to treatment.

Other inclusion applies

Exclusion Criteria:

• Patients with any concomitant condition that, in the opinion of the investigator, would preclude an evaluation of a response or make it unlikely that the contemplated course of therapy could be completed.
• Patients with severely impaired arterial blood supply and insufficiency such that the likelihood of amputation of the infected anatomical site within one month is likely.
• Infected diabetic foot ulcers or decubitus ulcers where the infection is present for greater than one week's duration or chronically infected decubitus ulcers in patients who can not be compliant with measures necessary for chronic wound healing.
• Necrotizing fasciitis or gangrene.

Other exclusion applies.