Ceftazidime-Avibactam Dosage for Complicated Infections
The recommended dosage of ceftazidime-avibactam for treating complicated infections is 2.5 grams (2 grams ceftazidime and 0.5 grams avibactam) administered intravenously every 8 hours as a 2-hour infusion. 1
Standard Dosing Regimens by Infection Type
Adult Patients (≥18 years) with Normal Renal Function (CrCl >50 mL/min)
Complicated Intra-abdominal Infections (cIAI):
Complicated Urinary Tract Infections (cUTI) including Pyelonephritis:
Hospital-acquired/Ventilator-associated Bacterial Pneumonia (HABP/VABP):
- Ceftazidime-avibactam: 2.5 g IV q8h as 2-hour infusion 1
- Duration: 7-14 days
Bloodstream Infections due to Carbapenem-resistant Enterobacterales (CRE):
- Ceftazidime-avibactam: 2.5 g IV q8h infused over 3 hours 2
- Duration: 7-14 days
Dosage Adjustments for Renal Impairment in Adults
| Creatinine Clearance (CrCl) | Recommended Dose |
|---|---|
| >50 mL/min | 2.5 g (2 g ceftazidime + 0.5 g avibactam) IV q8h |
| 31-50 mL/min | 1.25 g (1 g ceftazidime + 0.25 g avibactam) IV q8h |
| 16-30 mL/min | 0.94 g (0.75 g ceftazidime + 0.19 g avibactam) IV q12h |
| 6-15 mL/min | 0.94 g (0.75 g ceftazidime + 0.19 g avibactam) IV q24h |
| ≤5 mL/min | 0.94 g (0.75 g ceftazidime + 0.19 g avibactam) IV q48h |
Pediatric Dosing
Pediatric Patients (2 years to <18 years) with eGFR >50 mL/min/1.73 m²
- Ceftazidime-avibactam: 62.5 mg/kg to maximum of 2.5 g IV q8h as 2-hour infusion 1
Pediatric Patients (6 months to <2 years) without Renal Impairment
- Ceftazidime-avibactam: 62.5 mg/kg IV q8h as 2-hour infusion 1
Pediatric Patients (3 months to <6 months) without Renal Impairment
- Ceftazidime-avibactam: 50 mg/kg IV q8h as 2-hour infusion 1
Pediatric Patients (>28 days to <3 months) without Renal Impairment
- Ceftazidime-avibactam: 37.5 mg/kg IV q8h as 2-hour infusion 1
Neonates (≤28 days with GA ≥31 weeks) without Renal Impairment
- Ceftazidime-avibactam: 25 mg/kg IV q8h as 2-hour infusion 1
Clinical Considerations
Pharmacokinetic/Pharmacodynamic Properties
- Both ceftazidime and avibactam have complementary PK profiles with half-lives of approximately 2 hours 3
- The fixed-dose combination ratio of 4:1 (ceftazidime:avibactam) was established based on pharmacokinetic modeling 3
- Primary elimination pathway for both drugs is renal clearance 3
- Target attainment is based on:
Efficacy in Clinical Trials
- Ceftazidime-avibactam demonstrated non-inferiority to carbapenems in phase III studies for cIAI, cUTI, and nosocomial pneumonia 3, 5, 6
- In the REPRISE trial, clinical cure rates were similar between ceftazidime-avibactam (91%) and best available therapy (91%) for ceftazidime-resistant Enterobacteriaceae and Pseudomonas aeruginosa infections 5
Special Populations
- Critically ill patients: Standard dosing is appropriate as pharmacokinetic modeling accounts for this population 4, 6
- Patients on continuous renal replacement therapy: Limited data suggests dosing may need adjustment; consider monitoring drug levels if available 7
Key Clinical Pearls
- Always adjust dosing based on renal function and monitor renal function during treatment
- For cIAI, always administer with metronidazole for anaerobic coverage
- The 2-hour infusion time is critical for achieving optimal pharmacokinetic/pharmacodynamic targets
- For CRE bloodstream infections, a 3-hour infusion is recommended to optimize drug exposure
- Monitor for emerging resistance during therapy, particularly in settings with high prevalence of multidrug-resistant organisms
Ceftazidime-avibactam represents an important treatment option for complicated infections caused by resistant gram-negative pathogens, particularly as a carbapenem-sparing alternative when appropriate.