ceftazidime
Ceptaz, Fortaz, Tazicef, Tazidime

Pharmacologic classification: third-generation cephalosporin
Therapeutic classification: antibiotic
Pregnancy risk category B


Available forms
Available by prescription only
Infusion: 1 g, 2 g in 50- and 100-ml vials and bags
Injection: 500 mg, 1 g, 2 g

Indications and dosages
 Bacteremia, septicemia, and serious respiratory tract, urinary tract, gynecologic, bone and joint, intra-abdominal, CNS, and skin infections from susceptible organisms. Adults: 1 g I.V. or I.M. q 8 to 12 hours; up to 6 g daily in life-threatening infections.
Children ages 1 month to 12 years: 30 to 50 mg/kg I.V. q 8 hours to a maximum of 6 g daily (Fortaz, Tazicef, and Tazidime only).
Neonates up to age 4 weeks: 30 mg/kg I.V. q 12 hours (Fortaz, Tazicef, and Tazidime only).
Total daily dose is the same for I.M. or I.V. administration and depends on susceptibility of organism and severity of infection. Inject ceftazidime deep into a large muscle mass, such as the gluteus or lateral aspect of the thigh.
 Empiric therapy in febrile neutropenic patients ◇. Adults: 100 mg/kg I.V. daily in three divided doses; or 2 g I.V. q 8 hours either alone or with an aminoglycoside such as amikacin.
Children age 2 and older: 50 mg/kg (maximum 2 g) q 8 hours given I.V.
≡ Dosage adjustment. For patients with impaired renal function, doses or frequency of administration must be modified according to the degree of renal impairment, severity of infection, and susceptibility of organism. To prevent toxic accumulation, reduced dosage may be required in patients with creatinine clearance of 50 ml/ minute or less; initially, give 1 g loading dose and then follow maintenance recommendations.

Creatinine clearance (ml/min) Adult dosage

31-50 1 g q 12 hours
16-30 1 g q 24 hours
6-15 500 mg q 24 hours
≤ 5 500 mg q 48 hours
For hemodialysis patients, give a loading dose of 1 g followed by 1 g after each hemodialysis session. For peritoneal dialysis patients, give 500 mg q 24 hours.

Pharmacodynamics
Antibacterial action: Ceftazidime is primarily bactericidal; it also may be bacteriostatic. Activity depends on the organism, tissue penetration, dosage, and rate of organism multiplication. It acts by adhering to bacterial penicillin-binding proteins, thereby inhibiting cell wall synthesis. Third-generation cephalosporins appear to be more active against some beta-lactamase-producing gram-negative organisms.
Ceftazidime is active against some gram-positive organisms and many enteric gram-negative bacilli, as well as streptococci (Streptococcus pneumoniae and Streptococcus pyogenes); Staphylococcus aureus (penicillinase- and non-penicillinase-producing); Escherichia coli; Klebsiella species; Proteus species; Enterobacter species; Haemophilus influenzae; Pseudomonas species; and some strains of Bacteroides species. It’s more effective than any cephalosporin or penicillin derivative against Pseudomonas species. Some other third-generation cephalosporins are more active against gram-positive organisms and anaerobes.

Pharmacokinetics
Absorption: Administered I.V. and I.M.
Distribution: Distributed widely into most body tissues and fluids, including the gallbladder, liver, kidneys, bone, sputum, bile, and pleural and synovial fluids; unlike most other cephalosporins, ceftazidime has good CSF penetration; it crosses the placental barrier. Ceftazidime is 5% to 24% protein-bound.
Metabolism: Not metabolized.
Excretion: Excreted mainly in urine by glomerular filtration; small amounts of drug appear in breast milk. Elimination half-life is about 11/2 to 2 hours in patients with normal renal function; up to 35 hours in patients with severe renal disease. Hemodialysis or peritoneal dialysis removes ceftazidime.

Route Onset Peak Duration
I.V. Immediate Immediate Unknown
I.M. Unknown 1 hr Unknown


Contraindications and precautions
Contraindicated in patients hypersensitive to drug or other cephalosporins. Use cautiously in breast-feeding women and in patients with poor renal function or penicillin allergy.

Interactions
Drug-drug. Aminoglycosides: Exerts synergistic activity against some strains of Pseudomonas aeruginosa and Enterobacteriaceae; may increase risk of nephrotoxicity of cephalosporins. Monitor patient for effects.
Chloramphenicol: Causes antagonistic effect. Avoid use together.
Quinolones: In vitro studies show synergistic effect against Burkholderia cepacia. May be used for therapeutic effect.

Adverse reactions
CNS: seizures, fever.
CV: thrombophlebitis with I.V. injection, phlebitis.
GI: pseudomembranous colitis, nausea, vomiting, diarrhea, abdominal cramps.
GU: vaginitis.
Hematologic: eosinophilia, thrombocytosis, leukopenia, hemolytic anemia, agranulocytosis, thrombocytopenia.
Skin: pruritus, rash, inflammation at injection site.
Other: hypersensitivity reactions (serum sickness, anaphylaxis).

Effects on lab test results
• May increase ALT, AST, alkaline phosphatase, bilirubin, and LDH levels.
• May increase eosinophil count. May decrease hemoglobin, hematocrit, and WBC and granulocyte counts. May increase or decrease platelet count.

Overdose and treatment
Overdose may cause neuromuscular hypersensitivity. Seizures may follow high CNS levels.
 Drug may be removed by hemodialysis or peritoneal dialysis.

Special considerations
 ALERT Names of some cephalosporins are similar. Use caution when prescribing.
• For patients on sodium restriction, note that ceftazidime contains 2.3 mEq of sodium per gram of drug.
• Ceftazidime powders (excluding Ceptaz) for injection contain 118 mg sodium carbonate per gram of drug; ceftazidime sodium is more water-soluble and is formed in situ upon reconstitution.
• Vials are supplied under reduced pressure. When antibiotic is dissolved, carbon dioxide is released and a positive pressure develops. Each brand of ceftazidime includes specific instructions for reconstitution. Read instructions carefully.
• Because drug is hemodialyzable, patients undergoing treatments with hemodialysis or peritoneal dialysis may require dosage adjustment.
• Separate I.V. sites should be used for aminoglycosides and ceftazidime.
• Ceftazidime causes false-positive results in urine glucose tests using cupric sulfate (Benedict’s reagent or Clinitest); use glucose oxidase (Chemstrip uG, Diastix, or glucose enzymatic test strip) instead. Ceftazidime also causes false elevations in urine creatinine levels in tests using Jaffe reaction. Ceftazidime may cause positive Coombs’ test results.
• With large doses or prolonged therapy, patients (especially high-risk patients) must be observed for superinfection.
Pregnant patients
• Use only when clearly needed.
Breast-feeding patients
• Drug appears in breast milk; use cautiously in breast-feeding women. Safety hasn’t been established.
Pediatric patients
• Only Fortaz, Tazicef, and Tazidime may be used in infants and children. Ceptaz shouldn’t be used in children younger than age 12 because it contains arginine.
Geriatric patients
• Reduced dosage may be needed in elderly patients with diminished renal function.

Patient education
• Advise patient to report discomfort at I.V. site.
• Tell patient to report rash or symptoms of superinfection.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use