Z-Fix Mechanism of Action

Pharmacology: Pharmacokinetics: Only 40 to 50% of an oral dose of Cefixime is absorbed from the gastrointestinal tract, whether taken before or after meals, although the rate of absorption may be decreased in the presence of food. Cefixime is better absorbed from oral suspension than from tablets. Absorption is fairly slow; peak plasma concentrations of 2 to 3 micrograms/mL and 3.7 to 4.6 micrograms/mL have been reported between 2 and 6 hours after single doses of 200 and 400 mg, respectively. The plasma half-life is usually about 3 to 4 hours and may be prolonged when there is renal impairment. About 65% of Cefixime is bound to plasma proteins.
Information on the distribution of Cefixime in body tissues and fluids is limited. It crosses the placenta. Relatively high concentrations may be achieved in bile and urine. About 20% of an oral dose (or 50% of an absorbed dose) is excreted unchanged in the urine within 24 hours. Up to 6% may be eliminated by non renal mechanism; there is no evidence of metabolism but some is probably excreted in the feces from bile. It is not substantially removed by dialysis.
Antimicrobial Action: Cefixime is bactericidal and is stable to hydrolysis by many beta-lactamase. It has a mode of action and spectrum of activity similar to that of the third generation cephalosporin cefotaxime, but some enterobacteriaceae are less susceptible to Cefixime. Haemophilus influenzae, Moraxella catarrhalis (Branhamella catarrhalis) and Neisseria gonorrhoeae are sensitive, including penicillinase-producing strains of the Gram-positive bacteria, Streptococci are sensitive to Cefixime but most strains of Staphylococci, Enterococci and Listeria spp. are not. Enterobacter spp., Pseudomonas aeruginosa, and Bacteroides spp,. are resistant to Cefixime.