Description

Cefaclor is a second-generation cephalosporin antibiotic. It belongs to the beta-lactam class of antibiotics and is known for its broad-spectrum activity against a range of bacteria. Cefaclor is a semi-synthetic drug that is administered orally. A key characteristic of second-generation cephalosporins like cefaclor is their improved activity against certain Gram-negative bacteria compared to first-generation drugs, in addition to maintaining efficacy against many Gram-positive bacteria.

Indications

Cefaclor is used to treat a variety of bacterial infections. Its main indications include:

• Respiratory tract infections: Such as bronchitis, pneumonia, and pharyngitis.

• Urinary tract infections (UTIs): Such as pyelonephritis and cystitis.

• Skin and soft tissue infections: Including abscesses, cellulitis, and carbuncles.

• Otitis media (ear infections).

• Sinusitis.

Mechanism of Action

Cefaclor, like other beta-lactam antibiotics, works by inhibiting bacterial cell wall synthesis. Its mechanism of action is as follows:

1. Bacterial Cell Wall Synthesis: Bacteria require a rigid cell wall, made of a polymer called peptidoglycan, for structural integrity and survival. The final stage of this synthesis involves a cross-linking process carried out by enzymes called penicillin-binding proteins (PBPs).

2. Beta-Lactam Ring: The key feature of cefaclor is its beta-lactam ring. This ring has a similar structure to the D-alanyl-D-alanine portion of the peptidoglycan precursor.
3. Inhibition of PBPs: Cefaclor acts by binding to and inhibiting these PBPs. By binding to the active site of the enzymes, it prevents them from cross-linking the peptidoglycan strands.
4. Resulting Effect: This inhibition leads to the formation of a weak and defective bacterial cell wall. The weakened wall cannot withstand the internal osmotic pressure of the bacterium, causing the cell to swell and burst, a process known as lysis. This leads to bacterial cell death, making cefaclor a bactericidal (bacteria-killing) antibiotic.