Cefazolin

Oral Antibiotics

Drug class: First-Generation Cephalosporin Antibiotic, beta-lactam antibiotics class, specifically categorized as a First-generation cephalosporin.

Cefazolin (CEFAMEZIN)（中文：頭孢唑林）

Common Strengths

Cefazolin is available in injectable form:

• 1 g

Drug Trade Name

Cefamezin

Drug Usage

Cefazolin is used to treat a variety of bacterial infections, including:

• Respiratory tract infections
• Urinary tract infections
• Skin and soft tissue infections
• Bone and joint infections
• Bloodstream infections (sepsis)
• Endocarditis

It is also utilized for prophylaxis before and during certain surgical procedure to prevent infections.

Mechanism of Action

Cefazolin works by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs), which are essential for the final stages of peptidoglycan synthesis in the bacterial cell wall. This action leads to cell lysis and death, making cefazolin bactericidal.

Route of Administration

Cefazolin is administered intravenously (IV) or intramuscularly (IM)

Dosages

The dosage of cefazolin can vary based on the severity of the infection and patient factors such as renal function. General dosing guidelines include:

• Normal adults: 0.5 to 1 g IV every 6 to 8 hours for moderate to severe infections.

Renal Dosing Based on eGFR

Cefazolin dosing should be adjusted in patients with renal impairment. The typical adjustment is as follows:

• eGFR >60 mL/min: Standard dosing
• eGFR 30-60 mL/min: Reduce dose by 25%
• eGFR <30 mL/min: Reduce dose by 50%

Frequency	Adverse reactions
Common Side Effects	Diarrhea
	Nausea and vomiting
	Rash or allergic reactions
Serious Side Effects	Severe allergic reactions (anaphylaxis)
	Clostridium difficile-associated diarrhea
	Renal toxicity

Pharmacokinetics

Cefazolin has a rapid onset of action, typically within 30 minutes to 1 hour after administration. Its duration of action lasts approximately 6 to 12 hours.

Drug Precautions

Pregnancy

Cefazolin is generally considered safe during pregnancy; however, it should be used only if clearly needed.

Breastfeeding

Cefazolin is excreted in breast milk but is deemed compatible with breastfeeding according to the American Academy of Pediatrics.

Children and Elderly

Use with caution; dosage adjustments may be necessary based on age-related renal function changes.

Monitoring Items

Laboratory Tests: Regular checks are recommended for:

• Complete Blood Count (CBC): To monitor for potential hematological side effects like neutropenia.
• Renal Function: Serum creatinine and blood urea nitrogen (BUN) levels should be assessed, especially in patients with pre-existing renal impairment, as cefazolin is primarily excreted by the kidneys.
• Liver Function Tests: To detect any hepatic dysfunction that may arise during treatment.
• International Normalized Ratio (INR): Particularly important for patients on warfarin, as cefazolin can enhance the anticoagulant effect and increase bleeding risk.

In addition to laboratory tests, clinical monitoring involves:

• Allergy Assessment: Confirm that the patient dose not have a history of allergies to penicillins or cephalosporins.
• Signs of Infection Resolution: Monitor clinical signs and symptoms to evaluate the effectiveness of therapy.
• Adverse Reactions: Watch for gastrointestinal disturbances such as diarrhea, which could indicate C. difficile infection.

Drug Interactions

Cefazolin may interact with:

• Probenecid (may increase cefazolin levels)
• Anticoagulants (risk of increased bleeding)

FAQ

How Should I take Cefazolin?

Cefazolin is not available in tablet form; it is administered via injection.

What should I avoid during treatment?

Avoid alcohol during treatment due to potential disulfiram-like reactions. Monitor for signs of allergic reactions or gastrointestinal disturbances.