What is the recommended dosage of Zosyn (piperacillin/tazobactam) for treating pancolitis?

Zosyn (Piperacillin/Tazobactam) Dosage for Pancolitis

The recommended dosage of Zosyn (piperacillin/tazobactam) for treating pancolitis is 4.5 g administered intravenously every 6 hours. 1

Dosing Considerations

Standard Dosing

• Standard dose: 4.5 g IV every 6 hours 1
• Maximum daily dose: 18 g (4.5 g × 4 doses) 1
• Duration: Typically 4-7 days if adequate source control is achieved 2

Renal Adjustment

• CrCl 20-40 mL/min: 4.5 g IV every 8 hours 1
• CrCl <20 mL/min: 4.5 g IV every 12 hours 1
• Hemodialysis: 4.5 g IV every 12 hours plus an additional dose after each dialysis session 1

Pediatric Dosing

• For children: 200-300 mg/kg/day of piperacillin component divided every 6-8 hours 2
• Maximum: 4.5 g per dose 1

Clinical Application Algorithm

1. Assess Severity:

   • Non-severe pancolitis: Consider oral antibiotics or other therapies first
   • Severe or complicated pancolitis: Initiate Zosyn 4.5 g IV q6h 2
   • Septic shock: Consider extended infusion of Zosyn (3-4 hours instead of standard 30-minute infusions) 3

2. Source Control Assessment:

   • Adequate source control: Continue Zosyn for 4 days in immunocompetent patients 2
   • Inadequate source control: May require longer therapy (up to 7 days) 2
   • Immunocompromised patients: Consider extended therapy up to 7 days 2

3. Monitoring:

   • Evaluate clinical response within 48-72 hours
   • Monitor renal function regularly
   • If no improvement after 7 days, investigate for complications or resistant organisms 2

Special Considerations

Alternative Regimens

For patients with beta-lactam allergies, alternative options include:

• Eravacycline 1 mg/kg q12h 2
• Tigecycline 100 mg loading dose, then 50 mg q12h 2

Combination Therapy

In critically ill patients with septic shock, consider adding:

• Meropenem 1 g q6h by extended infusion 2
• Imipenem/cilastatin 500 mg q6h by extended infusion 2

Clinical Pearls and Pitfalls

Pearls

• Extended infusion (over 3-4 hours) may improve outcomes in critically ill patients compared to standard 30-minute infusions 3
• Generic formulations may have decreased activity (average -16%) compared to branded Zosyn, potentially equivalent to underdosing by 2.6 g daily 4

Pitfalls

• Underdosing in critically ill patients
• Failure to adjust for renal function
• Inadequate duration of therapy
• Missing source control, which can lead to treatment failure

Monitoring for Treatment Response

Treatment response should be assessed by:

• Decreased stool frequency
• Improved stool consistency
• Resolution of systemic inflammatory signs
• If no improvement after 3 days, reassess diagnosis and source control 2

Ongoing signs of infection beyond 7 days warrant further diagnostic investigation to identify complications or resistant organisms 2.