The primary objective is to study the efficacy of piperacillin/tazobactam in patients with complicated urinary tract infections

Inclusion Criteria:

• Hospitalized patients over 16 years of age with complicated urinary infection produced by bacteria that are suspected to be susceptible to treatment with Piperacillin-tazobactam.

Exclusion Criteria:

• Patients known, or thought to be hypersensitivity to beta-lactams
• Patients with an uncomplicated urinary tract infection

Patients treated at internal medicine units