Preferred regimen piperacillin/tazobactam (Tazocin®) 4.5 g IV 8 hourly plus Gentamicin* 5 mg/kg/day IV (Piperacillin/tazobactam (Tazocin®) requires approval from Infectious Diseases or Clinical Microbiology) In patients known to be colonised with, or at high risk of MRSA, vancomycin should be added.

Pneumonia Treatment: Hospitalized < 5 days: Refer to CAP Guidance for all patients including those with risk factors for resistance Hospitalized ≥ 5 days: Preferred: Vancomycin* plus cefepime OR Vancomycin plus piperacillin/tazobactam Severe beta-lactam allergy: Vancomycin* plus aztreonam

Table 3 lists options for antibiotic regimens for the empiric treatment of CAP in the inpatient setting. Omadacycline (Nuzyra), a newer tetracycline antibiotic, was shown to be as effective as moxifloxacin (Avelox) as monotherapy in adults with nonsevere CAP.

In patients with risk factors for MDROs, particularly with MRSA, vancomycin or linezolid is an appropriate first choice.

In the 2007 guidelines, the Infectious Diseases Society of America and the American Thoracic Society used very broad criteria for defining the population at risk of infection with antibiotic-resistant pathogens, which resulted in the majority of patients with HAP requiring broad-spectrum antibiotic therapy for MRSA and resistant Pseudomonas.