What is the recommended ceftazidime dosing for adults with normal renal function, for severe infections, for patients with impaired renal function, for pediatric patients, and for cystic fibrosis patients?

Ceftazidime Dosing Recommendations

Standard Adult Dosing (Normal Renal Function)

For adults with normal renal function, ceftazidime should be dosed at 1 gram IV every 8–12 hours for routine infections, with escalation to 2 grams IV every 8 hours for severe infections including hospital-acquired pneumonia, meningitis, serious intra-abdominal infections, and bone/joint infections. 1

• The 2 gram every 8 hours regimen is specifically recommended for late-onset hospital-acquired pneumonia, ventilator-associated pneumonia, and healthcare-associated pneumonia when multidrug-resistant pathogens are suspected 2
• For uncomplicated urinary tract infections, a reduced dose of 250 mg IV every 12 hours is sufficient 1
• Complicated urinary tract infections require 500 mg IV every 8–12 hours 1
• Uncomplicated pneumonia and mild skin/soft tissue infections warrant 500 mg to 1 gram IV every 8 hours 1

Severe and Life-Threatening Infections

Very severe life-threatening infections, particularly in immunocompromised patients, require the maximum dose of 2 grams IV every 8 hours (total 6 grams daily). 1

• For carbapenem-resistant Pseudomonas aeruginosa susceptible to ceftazidime, use 2 grams IV every 8 hours for 5–14 days, with longer courses (10–14 days) reserved for pneumonia and bloodstream infections 3
• Meningitis requires 2 grams IV every 8 hours 1
• Serious gynecologic and intra-abdominal infections necessitate 2 grams IV every 8 hours 1

Important Monitoring Consideration

• Monitor for neurotoxicity (seizures, encephalopathy, confusion), especially in patients with renal impairment where drug accumulation occurs 3

Dosing in Renal Impairment

Because ceftazidime is excreted almost exclusively by glomerular filtration, dose reduction is mandatory when creatinine clearance falls below 50 mL/min. 1, 4

Renal Dosing Algorithm

Start with a 1 gram loading dose, then adjust maintenance dosing based on creatinine clearance: 1

• CrCl 50–31 mL/min: 1 gram every 12 hours 1, 4
• CrCl 30–16 mL/min: 1 gram every 24 hours 1, 4
• CrCl 15–6 mL/min: 500 mg every 24 hours 1, 4
• CrCl <5 mL/min: 500 mg every 48 hours 1, 4

Critical Caveat for Severe Infections with Renal Impairment

• In patients with severe infections who would normally receive 6 grams daily but have renal insufficiency, the unit dose may be increased by 50% or dosing frequency increased, guided by therapeutic monitoring 1
• If the standard dose for the infection type (from Table 3 of the FDA label) is lower than the renal-adjusted dose, use the lower dose 1

Dialysis Patients

For hemodialysis patients: Give 1 gram loading dose, followed by 1 gram after each hemodialysis session 1, 5

For peritoneal dialysis patients: Give 1 gram loading dose (10 mg/kg), then 500 mg every 24 hours; ceftazidime can be incorporated into dialysis fluid at 250 mg per 2 L 1, 5

Pediatric Dosing

Infants and Children (1 Month to 12 Years)

The standard pediatric dose is 30–50 mg/kg IV every 8 hours, with a maximum of 6 grams per day. 1, 6

• The higher end of the dosing range (50 mg/kg every 8 hours) should be reserved for immunocompromised patients, those with cystic fibrosis, or meningitis 1, 6
• For severe infections including septicemia and meningitis, doses of 30–50 mg/kg IV every 8 hours are recommended 6
• Larger doses are necessary for cystic fibrosis patients, immunosuppressed children, meningitis, and infections caused by organisms with high MICs 6

Neonates (0–4 Weeks)

Neonates require 30 mg/kg IV every 12 hours. 1, 6

• This reduced frequency accounts for immature renal function in the neonatal period 6
• Dosing should be adjusted for body surface area or lean body mass, with frequency reduced in cases of renal insufficiency 1

Infants 3–6 Months

• For infants 3 to 6 months old with creatinine clearance >50 mL/min/1.73 m², use 40–10 mg/kg (ceftazidime-avibactam formulation) every 8 hours by 2-hour IV infusion 7

Children ≥6 Months to 18 Years

• For children 6 months to 18 years old with creatinine clearance >50 mL/min/1.73 m², use 50–12.5 mg/kg (maximum 2,000–500 mg for ceftazidime-avibactam) every 8 hours by 2-hour IV infusion 7

Cystic Fibrosis Patients

Cystic fibrosis patients with normal renal function require substantially higher doses: 30–50 mg/kg IV every 8 hours, up to a maximum of 6 grams per day. 1

• The European consensus recommends that previously recommended doses of <200 mg/kg may still be too low for CF patients when given intermittently 2
• A mean daily dose of 150 mg/kg is often necessary in septicemias and infections associated with cystic fibrosis 8
• Clinical improvement can be demonstrated, but bacteriologic cures cannot be expected in patients with chronic respiratory disease and cystic fibrosis 1
• Higher doses are required due to increased volume of distribution, enhanced renal clearance, and the endobronchial location of Pseudomonas aeruginosa infection with inaccessibility of mucoid organisms in mucus plugs 2

Important CF-Specific Considerations

• Appropriate airway clearance should be performed before administration of antibiotics to optimize drug penetration 2
• Combination therapy (typically with an aminoglycoside) is favored to slow resistance development and achieve synergy 2
• Intravenous therapy is generally scheduled for approximately 2 weeks but may be prolonged for another week based on clinical response 2

Duration of Therapy

Continue ceftazidime for 2 days after signs and symptoms of infection have disappeared; complicated infections may require longer therapy. 1

• For carbapenem-resistant Pseudomonas infections, treat for 5–14 days, with 10–14 day courses for pneumonia and bloodstream infections 3

Route of Administration

• Ceftazidime may be given intravenously or by deep intramuscular injection into a large muscle mass (upper outer quadrant of gluteus maximus or lateral thigh) 1
• Intra-arterial administration must be avoided 1