Ceftazidime exerts its bactericidal effect by inhibiting bacterial cell wall synthesis. According to the Lippincott Textbook of Pharmacology, ceftazidime binds to penicillin-binding proteins (PBPs) on the bacterial cell wall, disrupting peptidoglycan cross-linking. This weakens the cell wall, leading to osmotic instability and cell lysis.

The Lange Basic & Clinical Pharmacology highlights ceftazidime’s resistance to many beta-lactamases, including those produced by Pseudomonas aeruginosa. However, it is less effective against Gram-positive bacteria compared to other third-generation cephalosporins.

Ceftazidime is indicated for:

1. Severe Gram-Negative Infections:
   • Respiratory Tract Infections: Pneumonia (hospital-acquired and ventilator-associated).
   • Urinary Tract Infections (UTIs): Complicated pyelonephritis and cystitis.
   • Intra-Abdominal Infections: Peritonitis, biliary tract infections (in combination with metronidazole).
   • Skin and Soft Tissue Infections: Cellulitis, wound infections.
   • Septicemia: Bloodstream infections.
2. Cystic Fibrosis: Chronic Pseudomonas aeruginosa infections.
3. Febrile Neutropenia: Empiric therapy in immunocompromised patients.

The BNF emphasizes its role as a first-line agent for Pseudomonas infections and its use in combination therapy for severe infections.

Dosing varies by infection severity, patient age, and renal function:

Adults:

• Moderate Infections: 1 g IV/IM every 8–12 hours.
• Severe Infections (e.g., septicemia, pneumonia): 2 g IV every 8 hours.

Children (>2 months):

• 30–50 mg/kg/day IV/IM in divided doses every 8 hours (max 6 g/day).

Neonates:

• 30 mg/kg/day IV in divided doses every 12 hours.

Renal Impairment:

• Creatinine Clearance (CrCl) 31–50 mL/min: 1 g every 12 hours.
• CrCl 16–30 mL/min: 1 g every 24 hours.
• CrCl 6–15 mL/min: 500 mg every 24 hours.
• CrCl <5 mL/min: 500 mg every 48 hours.

Administration Tips:

• IV Infusion: Dilute in 50–100 mL of compatible fluid (e.g., 0.9% saline) and infuse over 30 minutes.

IM Injection: Reconstitute with lidocaine or sterile water to reduce discomfort

Ceftazidime is generally well-tolerated, but potential side effects include:

• Common:
  • Gastrointestinal disturbances (nausea, diarrhea).
  • Injection site reactions (pain, inflammation).
  • Rash or pruritus.
• Serious (Rare):
  • Hypersensitivity reactions (anaphylaxis, Stevens-Johnson syndrome).
  • Clostridioides difficile-associated diarrhea (CDAD).
  • Hematologic effects (neutropenia, thrombocytopenia).
  • Neurotoxicity (seizures, encephalopathy) – particularly in renal impairment or overdose.

1. Contraindications: Hypersensitivity to cephalosporins or severe beta-lactam allergy.
2. Renal Impairment: Dose adjustment is critical to avoid neurotoxicity.
3. Neurologic Monitoring: Monitor for seizures or confusion in patients with renal dysfunction or prolonged therapy.
4. Pregnancy and Lactation: Use only if benefits outweigh risks (limited safety data).
5. Cross-Reactivity: Low risk of cross-reactivity with penicillins (<1%), but caution is advised.

Key interactions per the BNF and Lange Basic & Clinical Pharmacology:

• Aminoglycosides: Synergistic against Gram-negative bacteria but may increase nephrotoxicity.
• Probenecid: Reduces renal excretion, increasing ceftazidime levels (avoid concurrent use).
• Oral Anticoagulants (e.g., warfarin): Enhanced anticoagulant effect (monitor INR).
• Loop Diuretics: May increase the risk of neurotoxicity.

• Generic: Ceftazidime pentahydrate.
• Brand Names: Fortaz®, Tazicef®, Ceptaz®.