Geotrixx Mechanism of Action

Antibacterial (Cephalosporin).
Pharmacology: Pharmacodynamics: Ceftriaxone is a cephalosporin/cephamycin beta-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually gram-positive, organisms. Ceftriaxone has in vitro activity against gram-positive aerobic, gram-negative aerobic, and anaerobic bacteria. The bactericidal activity of ceftriaxone results from the inhibition of cell wall synthesis and is mediated through ceftriaxone binding to penicillin-binding proteins (PBPs). Ceftriaxone is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, and cephalosporinases and extended-spectrum beta-lactamases. However, resistance to ceftriaxone usually occurs through beta-lactamase hydrolysis, altered PBPs, or reduced bacterial cell permeability. Ceftriaxone should not be mixed with or giving in the same IV line as diluents/products containing calcium as they may cause ceftriaxone to precipitate. Ceftriaxone use may also cause biliary sludge or gallbladder pseudolithiasis.
Pharmacokinetics: Pharmacokinetics in the Middle Ear Fluid: In one study, total ceftriaxone concentrations (bound and unbound) were measured in middle ear fluid obtained during the insertion of tympanostomy tubes in 42 pediatric patients with otitis media. Sampling times were from 1 to 50 hours after a single intramuscular injection of 50 mg/kg of ceftriaxone. Mean (±SD) ceftriaxone levels in the middle ear reached a peak of 35 (±12) μg/mL at 24 hours, and remained at 19 (±7) μg/mL at 48 hours. Based on middle ear fluid ceftriaxone concentrations in the 23 to 25 hour and the 46 to 50 hour sampling time intervals, a half-life of 25 hours was calculated. Ceftriaxone is highly bound to plasma proteins. The extent of binding to proteins in the middle ear fluid is unknown.