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Indications

• Bacterial infections
• Surgical prophylaxis
• Skin infections
• Soft tissue infections
• Bone infections
• Joint infections
• Lower urinary tract infections

Dosage

Children: Child 3–11 months: 12.5 mg/kg twice daily, alternatively 125 mg twice daily for

Adults: 500 mg 2–3 times a day for 7 to 10 days; in severe infections, the dose may be increased to 1–1.5 g 3–4 times a day.

Mechanism of action

Cefazolin exerts its bactericidal effects by inhibiting cell wall synthesis in bacteria. It binds to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, inhibiting the third and final stage of cell wall synthesis. This action prevents the cross-linkage of peptidoglycan chains, which is essential for maintaining bacterial cell wall strength. The inhibition of cell wall synthesis leads to cell lysis, particularly in rapidly dividing bacteria, which are most susceptible to cefazolin's action.

Pharmacodynamics

Cefazolin demonstrates broad-spectrum antibiotic activity due to its ability to inhibit bacterial cell wall synthesis. It is effective against a variety of pathogens, including Staphylococcus aureus and Escherichia coli. Its rapid excretion via the urine contributes to its effectiveness, allowing for high serum levels shortly after administration.

Pharmacokinetics

Cefazolin is administered parenterally and achieves peak serum concentrations quickly. It is widely distributed in body tissues and fluids, including bones and joints. The drug is primarily eliminated through the kidneys, with a significant portion excreted unchanged in the urine. The half-life of cefazolin is approximately 1.8 to 2.2 hours in individuals with normal renal function.

Adverse effects

• anxiety
• asthenia
• bo.ne marrow disorders
• chest pain
• confusion
• cough
• drowsiness
• dyspnoea
• epileptogenic activity
• gastrointestinal discomfort
• hyperglycaemia
• hypersensitivity
• hypoglycaemia
• increased leucocytes
• increased risk of infection
• jaundice
• lymphopenia
• malaise
• nephropathy
• proteinuria
• sleep disorders
• tongue swelling
• vertigo

Precautions

• Reduce dose in moderate impairment
• Use with caution in patients with a history of hypersensitivity to beta-lactam antibiotics

Pregnancy

Not known to be harmful.

Breast-feeding

Present in milk in low concentration, but appropriate to use.

Storage

Store at room temperature, away from moisture and light.

Formulations

• Intravenous injection
• Intravenous infusion
• Deep intramuscular injection

Dosage

Children: Refer to specific drug information for paediatric dosing recommendations based on clinical guidelines.

Adults: Refer to specific drug information for dosing recommendations based on clinical guidelines.

Mechanism of action

The mechanism of action of a drug described as equivalent will depend on the specific active ingredient it contains. For example, if the equivalent drug is an antifungal agent, it may inhibit the synthesis of ergosterol in fungal cell membranes, leading to cell death. Each drug's equivalency is confirmed through pharmacokinetic studies that assess absorption, distribution, metabolism, and excretion.

Pharmacodynamics

Pharmacodynamics refers to the effects of the drug on the body, including the relationship between drug concentration and therapeutic or toxic effects. Equivalent drugs should exhibit similar pharmacodynamic profiles, meaning they should produce comparable therapeutic effects at similar doses. Factors such as receptor binding, drug interactions, and the dose-response relationship are critical in determining the pharmacodynamic properties of the equivalent drug.

Pharmacokinetics

Pharmacokinetics involves the study of how a drug is absorbed, distributed, metabolized, and excreted in the body. For equivalent drugs, pharmacokinetic parameters like peak plasma concentration, time to peak concentration, bioavailability, volume of distribution, half-life, and clearance rates should be similar to those of the reference drug. Variations in these parameters can affect the efficacy and safety of the equivalent formulation.

Pregnancy

Consult healthcare provider as safety during pregnancy has not been established.

Breast-feeding

Consult healthcare provider as safety during breastfeeding has not been established.

Storage

Store in a cool, dry place away from direct sunlight.

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. Bactericidal; action depends on ability to reach and bind penicillin-binding proteins located in bacterial cytoplasmic membranes; cephalosporins inhibit bacterial septum and cell wall synthesis, probably by acylation of membrane-bound transpeptidase enzymes. This prevents cross-linkage of peptidoglycan chains, which is necessary for bacterial cell wall strength and rigidity. Also, cell division and growth are inhibited, and lysis and elongation of susceptible bacteria frequently occur. Rapidly dividing bacteria are those most susceptible to the action of cephalosporins. /Cephalosporins/

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.