Introduction
A semisynthetic cephalosporin analog with broad-spectrum antibiotic action due to inhibition of bacterial cell wall synthesis. It attains high serum levels and is excreted quickly via the urine.
Uses
Cefazolin is a broad-spectrum cephalosporin antibiotic mainly used for the treatment of skin bacterial infections and other moderate to severe bacterial infections in the lung, bone, joint, stomach, blood, heart valve, and urinary tract.
Mainly used to treat bacterial infections of the skin. It can also be used to treat moderately severe bacterial infections involving the lung, bone, joint, stomach, blood, heart valve, and urinary tract. It is clinically effective against infections caused by staphylococci and streptococci species of Gram positive bacteria. May be used for surgical prophylaxis; if required metronidazole may be added to cover B. fragilis.
Associated Conditions
Pharmacodynamics
Cefazolin (also known as cefazoline or cephazolin) is a semi-synthetic first generation cephalosporin for parenteral administration. Cefazolin has broad-spectrum antibiotic action due to inhibition of bacterial cell wall synthesis. It attains high serum levels and is excreted quickly via the urine.
Mechanism of Action
In vitro tests demonstrate that the bactericidal action of cephalosporins results from inhibition of cell wall synthesis. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, it inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins.
Absorption
Not absorbed from GI tract. Must be administered parenterally. Peak serum concentrations attained 1-2 hours post intramuscular injection.
Protein Binding
74-86%
Route of Elimination
Cefazolin is present in very low concentrations in the milk of nursing mothers. Cefazolin is excreted unchanged in the urine. In the first six hours approximately 60% of the drug is excreted in the urine and this increases to 70%-80% within 24 hours.
Half Life
The serum half-life is approximately 1.8 hours following IV administration and approximately 2.0 hours following IM administration.
Food Interactions
No interactions found.
Dosage
- Moderate to severe infection: 500 mg to 1 gm for every 6 to 8 hours
- Mild infections caused by susceptible Gram-positive cocci: 250 mg to 500 mg for every 8 hours
- Acute uncomplicated urinary tract infections: 1 gm for every 12 hours
- Pneumococcal pneumonia: 500 mg for every 12 hours
- Severe life-threatening infections (e.g. Endocarditis, Septicemia): 1 gm to 1.5 gm for every 6 hours. In rare instances, doses up to 12 gm per day can be used
- 1 gm IM or IV administered half hour to 1 hour prior to the start of surgery.
- For lengthy operative procedures (e.g. 2 hours or more), 500 mg to 1 gm IM or IV during surgery.
- 500 mg to 1 gm IM or IV every 6 to 8 hours for 24 hours postoperatively.
