Zinnat Mechanism of Action

Pharmacology: Pharmacodynamics: The prevalence of acquired resistance is geographically and time dependent and for select species may be very high. Local information on resistance is desirable, particularly when treating severe infections. (See Table 1.)

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Pharmacokinetics: Absorption: After oral administration cefuroxime (as axetil) (Zinnat) is absorbed from the gastrointestinal tract and rapidly hydrolysed in the intestinal mucosa and blood to release cefuroxime into the circulation.
Following administration of cefuroxime (as axetil) (Zinnat) tablets peak serum levels (2.1 mg/l for a 125 mg dose, 4.1 mg/l for a 250 mg dose, 7.0 mg/l for a 500 mg dose and 13.6 mg/l for a 1 g dose) occur approximately 2 to 3 hours after dosing when taken after food.
Tablet: Optimum absorption occurs when it is administered shortly after a meal.
Suspension: Absorption of cefuroxime axetil suspension is enhanced in the presence of food.
The rate of absorption of cefuroxime from the suspension is reduced compared with the tablets, leading to later, lower peak serum levels and reduced systemic bioavailability (4 to 17% less).
Distribution: Protein binding has been variously stated as 33 to 50% depending on the methodology used.
Metabolism: Cefuroxime is not metabolized.
Elimination: The serum half-life is between 1 and 1.5 hours.
Cefuroxime is excreted by glomerular filtration and tubular secretion. Concurrent administration of probenecid increases the area under the mean serum concentrations time curve by 50%.
Renal impairment: Cefuroxime pharmacokinetics have been investigated in patients with various degrees of renal impairment. Cefuroxime elimination half-life increases with decrease in renal function which serves as the basis for dosage adjustment recommendations in this group of patients (see Dosage & Administration). In patients undergoing haemodialysis, at least 60% of the total amount of cefuroxime present in the body at the start of dialysis will be removed during a 4-hour dialysis period. Therefore, an additional single dose of cefuroxime should be administered following the completion of haemodialysis.
Toxicology: Non-Clinical Information: Animal toxicity studies indicated that cefuroxime axetil is of low toxicity with no significant findings.