Ceftazidime%2520avibactam

# Ceftazidime-avibactam ## Overview Ceftazidime-avibactam is a combination cephalosporin antibiotic and beta-lactamase inhibitor. Avibactam restores ceftazidime activity against many organisms producing Ambler class A (e.g., KPC), class C (AmpC), and some class D beta-lactamases. ## Primary Indications * Complicated intra-abdominal infections (cIAI) (in combination with metronidazole). * Complicated urinary tract infections (cUTI), including pyelonephritis. * Hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP). ## Adult Dosing Standard dose is **2.5 g (ceftazidime 2 g/avibactam 0.5 g) IV every 8 hours**. * **Duration:** 5–14 days depending on infection site and severity. * **cIAI:** Must be administered with metronidazole (500 mg IV q8h). ## Pediatric Dosing FDA-approved for patients aged $\ge$ 3 months. Dosing is weight-based (based on ceftazidime component): * **3 months to < 6 months:** 40 mg/kg (ceftazidime) IV q8h. * **6 months to < 18 years:** 50 mg/kg (up to maximum 2 g ceftazidime) IV q8h. * *Note: Always consult institutional guidelines for neonatal/infant adjustments.* ## 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 0.75g/avibactam 0.1875g) q12h. * **CrCl 6–15 mL/min:** 0.94 g (ceftazidime 0.75g/avibactam 0.1875g) q24h. * **CrCl ≤ 5 mL/min:** 0.94 g (ceftazidime 0.75g/avibactam 0.1875g) every 48 hours. ## Contraindications * Known hypersensitivity to ceftazidime, avibactam, or any cephalosporin. * History of severe hypersensitivity to other beta-lactams (e.g., anaphylaxis). ## Adverse Effects * **Common:** Nausea, vomiting, diarrhea, constipation. * **Hematologic:** Coombs test seroconversion (risk of hemolytic anemia). * **CNS:** Anxiety, dizziness, rarely seizures (especially in renal impairment). * **Hepatic:** Elevated ALT/AST. ## Key Drug Interactions * **Probenecid:** Inhibits renal tubular secretion of ceftazidime; avoid concurrent use. * **Vaccines:** May decrease efficacy of live typhoid vaccine. ## Monitoring * **Renal function:** Monitor daily, especially in patients with fluctuating CrCl. * **Neurological:** Monitor for signs of neurotoxicity (confusion, myoclonus, seizures), particularly if renally impaired. * **Clinical response:** Resolution of fever and source-specific symptoms. ## Clinical Pearls * **Spectrum:** Excellent activity against carbapenem-resistant *Enterobacteriaceae* (CRE) and *Pseudomonas aeruginosa* (multidrug-resistant strains). * **Excluded Pathogens:** Does not cover *Acinetobacter* species or anaerobes (hence the mandatory addition of metronidazole for cIAI). * **Administration:** Administer as a 2-hour IV infusion. * **Resistance:** Use judiciously to prevent the emergence of new metallo-beta-lactamase (MBL) resistance, against which this drug is ineffective. *** **Disclaimer:** This information is for educational purposes and does not replace professional medical judgment. Always verify dosages, contraindications, and drug compatibility through your institution’s clinical pharmacy department or the latest official prescribing information (package insert) before administration.