Pharmacology Of Ceftriaxone

Indication For the treatment of the infections (respiratory, skin, soft tissue, UTI, ENT) caused by S. pneumoniae, H. influenzae, staphylococci, S. pyogenes (group A beta-hemolytic streptococci), E. coli, P. mirabilis, Klebsiella sp, coagulase-negative staph
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 and 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.
Mechanism of action Ceftriaxone works by inhibiting the mucopeptide synthesis in the bacterial cell wall. The beta-lactam moiety of Ceftriaxone binds to carboxypeptidases, endopeptidases, and transpeptidases in the bacterial cytoplasmic membrane. These enzymes are involved in cell-wall synthesis and cell division. By binding to these enzymes, Ceftriaxone results in the formation of of defective cell walls and cell death.
Absorption Not Available
Volume of distribution
  • 5.78 to 13.5 L
Protein binding 95%
Metabolism Not Available
Route of elimination Thirty-three percent to 67% of a ceftriaxone dose was excreted in the urine as unchanged drug and the remainder was secreted in the bile and ultimately found in the feces as microbiologically inactive compounds.
Half life 5.8-8.7 hours
Clearance
  • 0.58 – 1.45 L/h [healthy adults receiving 0.15-3 g of CEFTRIAXONE]
Toxicity Not Available