Cephalosporins類抗生素 (一代)

Respiratory tract, skin, genital, urinary tract, biliary tract, bone and joint infections, and septicemia; surgical prophylaxis:
due to susceptible gram (+) cocci (except enterococcus); some gram (-) bacilli including E. coli, Proteus, Klebsiella

First-generation cephalosporin
Active against most Gram (+) aerobic organisms except enterococci and some Gram (-) bacilli (eg, E. coli , Klebsiella pneumoniae, Proteus mirabilis)

Distribution
1. Widely into most body tissues and fluids but CSF penetration is poor
2. Protein binding: 74% to 86%
Excretion:
70-80% as unchanged drug
Elimination half-life:
90-150 min, prolonged with renal impairment; moderately dialyzed by dialysis

Hypersensitivity to cefazolin, other cephalosporin antibiotics, penicillins, other beta-lactams, or any component of the formulation

B

Infant risk is minimal.

Common: pruritus, diarrhea, drug-induced eosinophilia
Serious: allergic reaction, Stevens Johnson syndrome, pseudomembranous enterocolitis, hepatoxicity, leukopenia, thrombocytopenia

Bloodstream infection:
(IV) 2g Q8H, usual duration is 7-14 days (Enterobacteriaceae), >14 days (Staphylococcus aureus)
Endocarditis:
1. Native valve: (IV) 2 g Q8H for 6 weeks
2. Prosthetic valve: (IV) 2 g Q8H for >6 weeks (combine with rifampin for entire duration of therapy and gentamicin for the first 2 weeks)
Cholecystitis: (IV) 1-2g Q8H ; continue for 1 day after gallbladder removal or until clinical resolution in patients managed nonoperatively
Osteomyelitis:
1. Treatment for methicillin-susceptible S. aureus: (IV) 2 g every 8 hours for >6 weeks depending on extent of infection, debridement, and clinical response
2. Prevention following open fractures: (IV) 2 g for patients <120 kg or 3 g for patients >120 kg every 8 hours; ideally administer within 6 hours of injury.
Pneumonia:
1. (IV) 2g Q8H, for methicillin-susceptible S. aureus
2. Minimum duration is 5 to 7 days; patients should be clinically stable with normal vital signs before therapy is discontinued
Acute prostatitis: 1 g every 8 hours; may switch to oral therapy 24 to 48 hours after improvement in fever and clinical symptoms. Total duration of therapy is 4 to 6 weeks.

1. ClCr> 55: 1 gm Q6-8H
2. ClCr 35-54: 1gm Q8-12H
3. ClCr 11-34: 0.5-1 gm Q12H
4. ClCr < 10: 0.5-1 gm Q24H