Tricexone Mechanism of Action

Pharmacology: Pharmacodynamics: Ceftriaxone is a third-generation cephalosporin that is used for a variety of infections such as meningitis, gonorrhoea and community-acquired pneumonia. The most important aspects of its pharmacokinetics include a long half-life, excellent tissue penetration and saturable (dose-dependent) serum protein binding of the drug.
Pharmacokinetics: The pharmacokinetics of Ceftriaxone is largely determined by its concentration-dependent binding to plasma albumin. The plasma free (unbound) fraction of the drug in man is approximately 5% over most of the therapeutic concentration range, increasing to 15% at concentrations of 300 mg/L. Owing to the lower albumin content, the proportion of free Ceftriaxone in interstitial fluid is correspondingly higher than in plasma.
Plasma concentrations: Mean peak concentrations after bolus intravenous injection are about 120 mg/L following a 500 mg dose and about 200 mg/L following a 1 g dose; mean levels of 250 mg/L are achieved after infusion of 2 g over 30 minutes. Bioavailability after intramuscular injection is 100%.
Excretion: Ceftriaxone is eliminated mainly as unchanged drug, approximately 60% of the dose being excreted in the urine (almost exclusively by glomerular filtration) and the remainder via the biliary and intestinal tracts. The total plasma clearance is 10-22 mL/min. The renal clearance is 5-12 mL/min. A notable feature of Ceftriaxone is its relatively long plasma elimination half-life of approximately eight hours which makes single or once daily dosage of the drug appropriate for most patients. The half-life is not significantly affected by the dose, the route of administration or by repeated administration.