What is the mechanism of Cefuroxime Axetil?

Cefuroxime axetil is a second-generation cephalosporin antibiotic commonly used to treat a variety of bacterial infections. Its mechanism of action, pharmacokinetics, and therapeutic applications make it a critical tool in modern medicine.

Cefuroxime axetil is a prodrug, which means it is an inactive compound that is metabolized in the body to produce an active drug. Once ingested, cefuroxime axetil is absorbed from the gastrointestinal tract and esterases in the intestinal mucosa and blood rapidly hydrolyze it to its active form, cefuroxime.

Cefuroxime itself functions by interfering with bacterial cell wall synthesis. It achieves this by binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall. PBPs are enzymes that play a critical role in the cross-linking of the peptidoglycan layer, which provides mechanical strength and rigidity to the bacterial cell wall. By binding to these PBPs, cefuroxime inhibits their activity, leading to the formation of defective cell walls and ultimately causing bacterial cell lysis and death. This bactericidal activity is effective against a wide range of gram-positive and gram-negative bacteria.

The pharmacokinetics of cefuroxime axetil are noteworthy. After oral administration, the absorption of cefuroxime axetil is enhanced when taken with food. Peak plasma concentrations are typically achieved within 2 to 3 hours. The bioavailability of cefuroxime axetil is approximately 50% when taken with food, which decreases to about 37% when taken on an empty stomach. Once absorbed, cefuroxime is widely distributed throughout the body, including penetration into cerebrospinal fluid when the meninges are inflamed. It is primarily excreted unchanged in the urine, with a plasma half-life of approximately 1 to 1.5 hours in individuals with normal renal function.

Therapeutically, cefuroxime axetil is indicated for the treatment of a variety of infections, including respiratory tract infections, urinary tract infections, skin and soft tissue infections, and Lyme disease. It is particularly valuable due to its stability against beta-lactamases, enzymes produced by certain bacteria that can inactivate many other beta-lactam antibiotics. This makes cefuroxime axetil a versatile option for treating infections caused by beta-lactamase-producing organisms.

In summary, the mechanism of cefuroxime axetil involves its conversion to the active form, cefuroxime, which then disrupts bacterial cell wall synthesis by inhibiting penicillin-binding proteins. This action leads to the destruction of the bacterial cell. Its effective absorption, especially when taken with food, and its broad spectrum of activity against gram-positive and gram-negative bacteria make it an essential antibiotic in clinical practice. Understanding its mechanism and pharmacokinetics helps in optimizing its use for treating various bacterial infections.