CEFTAZIDIME
Clinical safety rating: safe
Human studies have proved safety
Ceftazidime is a third-generation cephalosporin antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death. It has broad-spectrum activity against Gram-negative bacteria, including Pseudomonas aeruginosa.
| Metabolism | Ceftazidime is not metabolized; it is excreted unchanged in the urine via glomerular filtration. Approximately 80-90% of a dose is recovered in the urine within 24 hours. |
| Excretion | Primarily renal: 80-90% excreted unchanged in urine via glomerular filtration; small amount (≈1%) biliary; ≤1% fecal. |
| Half-life | 2 hours (range 1.2-2.2 h) in normal renal function; prolonged to 10-15 h in end-stage renal disease; requires dose adjustment. |
| Protein binding | 10-17% (low binding; primarily to albumin). |
| Volume of Distribution | 0.13-0.22 L/kg; low Vd indicates limited tissue penetration; increased in neonates. |
| Bioavailability | IM: 90-100% (well absorbed); IV: 100%. |
| Onset of Action | IM: 1-2 hours; IV: immediate after bolus; infusion: within 30 minutes. |
| Duration of Action | 8-12 hours (dosing interval q8h); prolonged in renal impairment. |
1-2 g IV every 8 hours
| Dosage form | INJECTABLE |
| Renal impairment | 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 |
| Liver impairment | No adjustment required; see renal adjustment |
| Pediatric use | ≥1 month: 30-50 mg/kg IV every 8 hours; max 2 g per dose |
| Geriatric use | Base dose on renal function; see renal adjustment |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Probenecid may decrease cephalosporin excretion May cause diarrhea including Clostridium difficile-associated diarrhea.
| Breastfeeding | Ceftazidime is excreted into human breast milk in low concentrations. The milk-to-plasma (M/P) ratio is approximately 0.04-0.21. Based on this, the estimated daily dose to the infant is less than 1% of the maternal therapeutic dose. It is considered compatible with breastfeeding by the American Academy of Pediatrics. However, caution is advised, especially in neonates or infants with renal impairment, due to potential for alteration of gut flora and direct effects. |
| Teratogenic Risk | Ceftazidime is classified as FDA Pregnancy Category B. Animal studies have not demonstrated fetal risk, and there are no adequate, well-controlled studies in pregnant women. It should be used during pregnancy only if clearly needed. Based on available data, ceftazidime does not appear to be associated with major teratogenic effects when used in the first trimester. However, exposure during the second and third trimesters may be considered relatively safe, but data are limited to case reports and small studies. |
■ FDA Black Box Warning
No FDA black box warning.
| Common Effects | Diarrhea |
| Serious Effects |
Hypersensitivity to ceftazidime, any component of the formulation, or other cephalosporins.
| Precautions | Hypersensitivity reactions (including anaphylaxis) in patients with penicillin or other beta-lactam allergies; Clostridioides difficile-associated diarrhea; neurotoxicity (seizures, encephalopathy) especially with renal impairment; renal function monitoring; bleeding risk due to hypoprothrombinemia; superinfection; use in pregnancy and lactation. |
| Food/Dietary | No significant food interactions. However, note that alcohol may cause a disulfiram-like reaction (flushing, headache, nausea, vomiting, tachycardia) due to the methylthiotetrazole side chain. Avoid alcohol during therapy and for 48 hours after completion. |
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| Fetal Monitoring | Monitor maternal renal function and complete blood count (CBC) during prolonged therapy. No specific fetal monitoring is required, but assess fetal growth and well-being via ultrasound if maternal infection is severe or prolonged. Observe for signs of maternal adverse reactions including hypersensitivity, diarrhea, or Clostridioides difficile infection. |
| Fertility Effects | No specific studies on human fertility. Animal studies have not shown evidence of impaired fertility. No clinically significant effects on reproductive function are reported. |
| Clinical Pearls | Ceftazidime is a third-generation cephalosporin with potent activity against Pseudomonas aeruginosa. It is often used in combination with other agents for empiric coverage in febrile neutropenia. Note that ceftazidime has poor activity against gram-positive organisms and anaerobes; consider adding vancomycin or metronidazole if these pathogens are suspected. Dose adjustment is required in renal impairment; calculate CrCl before administration. Avoid in patients with cephalosporin allergy or severe penicillin hypersensitivity (risk of cross-reactivity). |
| Patient Advice | Take ceftazidime exactly as prescribed; complete the full course even if you feel better. · If you experience severe diarrhea, especially with blood or mucus, contact your doctor immediately. · Report any signs of allergic reaction: rash, itching, swelling, or difficulty breathing. · Avoid alcohol during treatment and for at least 48 hours after the last dose to prevent disulfiram-like reaction. · Notify your doctor if you have a history of penicillin allergy or kidney disease. |