Ceftazidime%25252525252520avibactam

# Ceftazidime-avibactam ## Overview Ceftazidime-avibactam (Avycaz) is a combination cephalosporin antibiotic and non-beta-lactam beta-lactamase inhibitor. It extends the spectrum of ceftazidime to include most Class A (KPC, ESBL), Class C (AmpC), and some Class D (OXA-48) beta-lactamases. It lacks activity against metallo-beta-lactamases (e.g., NDM-1). ## Primary Indications * Complicated intra-abdominal infections (cIAI) in combination with metronidazole. * Complicated urinary tract infections (cUTI), including pyelonephritis. * Hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP). ## Adult Dosing Standard dose is **2.5 g (ceftazidime 2 g/avibactam 500 mg) intravenously (IV) every 8 hours**. Infusion duration is 2 hours. ## Pediatric Dosing Patients $\ge$3 months of age: Dosing is weight-based. * **3 months to <6 months:** 40 mg/kg (ceftazidime) / 10 mg/kg (avibactam) IV q8h. * **6 months to <18 years:** * Weight <40 kg: 50 mg/kg (ceftazidime) / 12.5 mg/kg (avibactam) IV q8h. * Weight $\ge$40 kg: 2.5 g (ceftazidime 2 g/avibactam 500 mg) IV q8h. * *Note: All pediatric doses should be infused over 2 hours.* ## Dose Adjustments Renal impairment requires dose reduction based on estimated CrCl (Cockcroft-Gault). * **CrCl 31–50 mL/min:** 1.25 g q8h. * **CrCl 16–30 mL/min:** 0.94 g (ceftazidime 750 mg/avibactam 187.5 mg) q12h. * **CrCl 6–15 mL/min:** 0.94 g q24h. * **CrCl $\le$5 mL/min:** 0.94 g q48h. * **ESRD/Hemodialysis:** Administer the dose after dialysis on dialysis days. ## Contraindications Known hypersensitivity to ceftazidime, avibactam, or any component of the formulation; severe hypersensitivity (e.g., anaphylaxis) to any other cephalosporin. ## Adverse Effects * **Common:** Vomiting, nausea, constipation, diarrhea, anxiety, and pyrexia. * **Serious:** *Clostridioides difficile*-associated diarrhea, hypersensitivity reactions, seizures (primarily in patients with renal impairment who did not receive dose adjustments). ## Key Drug Interactions * **Probenecid:** May increase serum concentrations of ceftazidime; co-administration is generally not recommended. * **Other:** Limited cytochrome P450 interactions, as avibactam is not a significant enzyme inducer/inhibitor. ## Monitoring * **Renal function:** Adjust dosage continuously as CrCl fluctuates. * **Neurological:** Monitor for signs of neurotoxicity (seizures, confusion) in patients with renal impairment. * **Clinical:** Efficacy of therapy (fever resolution, WBC count, inflammatory markers). * **Safety:** Monitor for signs of *C. difficile* infection and allergic reactions. ## Clinical Pearls * **Spectrum:** It is not effective against *Acinetobacter baumannii* or anaerobic pathogens; metronidazole must be added for cIAI. * **Infusion:** Always infuse over 2 hours to optimize time above the minimum inhibitory concentration (T > MIC). * **Resistance:** While it covers many carbapenem-resistant Enterobacterales, it remains inactive against metallo-beta-lactamase producers. Consult local antibiograms or infectious disease specialists for site-specific resistance patterns. *** **Educational Disclaimer:** This information is for educational purposes only. Clinical practice varies by institution. Always verify dosages, contraindications, and compatibility with the most current official prescribing information (package insert) and your institution’s pharmacy clinical guidelines before prescribing or administering medication.