Tazidem Mechanism of Action

Pharmacology: Pharmacokinetics: Ceftazidime is given by injection as the sodium salt or in solution with arginine. Mean peak plasma concentrations of 17 and 39 mcg/mL have been reported about 1 hour after intramuscular doses of 0.5 and 1g of ceftazidime, respectively. Five minutes after intravenous bolus injections of 0.5, 1, and 2g of ceftazidime, mean plasma concentrations of 45, 90, and 170 mcg/mL, respectively, have been reported. The plasma half-life of ceftazidime is about 2 hours, but this is prolonged in patients with renal impairment and in neonates. Clearance may be enhanced in patients with cystic fibrosis. It is about 10% bound to plasma proteins.
Ceftazidime is widely distributed in body tissues and fluids; therapeutic concentrations are achieved in the CSF when the meninges are inflamed. It crosses the placenta and is distributed into breast milk.
Ceftazidime is passively excreted in bile, although only a small proportion is eliminated by this route. It is mainly excreted by the kidneys, almost exclusively by glomerular filtration; probenecid has little effect on the excretion. About 80 to 90% of a dose appears unchanged in the urine within 24 hours. It is removed by haemodialysis and peritoneal dialysis.