Indications
Cefixime is a third-generation cephalosporin antibiotic, indicated for the treatment of several bacterial infections. It is effective against uncomplicated urinary tract infections caused primarily by Escherichia coli and Proteus mirabilis. Additionally, cefixime is prescribed for otitis media due to Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pyogenes. It is also utilized in the management of pharyng·hronic bronchitis associated with Streptococcus pneumoniae and Haemophilus influenzae. Furthermore, cefixime addresses uncomplicated gonorrhea infections of the cervical or urethral regions, caused by both penicillinase-producing·hoeae.
Pharmacodynamics
Cefixime functions as an orally active, broad-spectrum, third-generation cephalosporin. Its primary mechanism of action involves inhibiting·hesis. Unlike some antibiotics, cefixime exhibits stability in the presence of certain beta-lactamase enzymes, which allows it to retain efficacy against organisms that have developed resistance to both penicillins and other cephalosporins with beta-lactamase resistance. However, patients should be aware of possible hypersensitivity reactions, including·hylactic responses, and the risk of Clostridium difficile-associated diarrhea (CDAD). Cefixime may also lower prothrombin activity, necessitating·h renal impairment or those undergoing·hemodialysis (HD). Monitoring·he oral administration of cefixime results in an absorption rate of approximately 40%-50%, irrespective of food intake, though concurrent food consumption may delay the time to reach maximum plasma concentration (Tmax) by about 0.8 hours. In studies involving·healthy male volunteers, a sing·hours post-administration. When administered as a 200 mg oral solution or capsule, the Cmax was observed at 3.22 micrograms/mL and 2.92 micrograms/mL, respectively. A 400 mg capsule resulted in a Cmax of 4.84 micrograms/mL. The respective mean areas under the plasma concentration-time curve (AUC) for cefixime administered as a 200 mg intravenous solution, 200 mg oral solution, 200 mg capsule, and 400 mg capsule were 47.0 μg.h/mL, 26.0 μg.h/mL, 23.6 μg.h/mL, and 39.4 μg.h/mL.
Metabolism
There is no evidence suggesting·hat cefixime undergoes metabolism within the human body. This characteristic may influence its pharmacokinetic profile and clinical use.
Mechanism of Action
Cefixime, a cephalosporin antibiotic, functions by disrupting bacterial cell wall synthesis, a crucial component for bacterial survival and proliferation. It achieves this by binding to penicillin-binding proteins (PBPs), specifically the transpeptidases, which play a critical role in the cross-linking of peptidoglycan strands, an essential process for maintaining cell wall integrity and structure. By inhibiting these key enzymes, cefixime compromises the formation of the bacterial cell wall, leading to cellular lysis, particularly in rapidly dividing bacteria. This mechanism ultimately results in the bactericidal effect of cefixime, effectively eliminating the bacterial threat by preventing the synthesis of the robust 3D peptidoglycan network necessary for bacterial cell wall strength and viability.
