Pharmacodynamics
Cefuroxime is a beta-lactam antibiotic. Its action is based on the inhibition of cell wall synthesis of bacteria. By binding to specific penicillin-binding proteins (PBPs) located within the bacterial cell wall, the third and final stage of bacterial cell wall synthesis is inhibited. As a result, cross-links important for stability can no longer be formed and the pathogen's cell wall disintegrates. Cell lysis is then mediated by autolytic enzymes of the bacterial cell wall such as autolysins; It is possible that cefuroxime interferes with an autolysin inhibitor.
Pharmacokinetics
Cefuroxime is absorbed from the gastrointestinal tract. Absorption is greater when cefuroxime is taken after meals (absolute bioavailability increases from 37% to 52%). Protein binding is 50%. Half-life is approximately 80 minutes after intramuscular or intravenous injection.
Drug Interactions
- Medications used to reduce gastric acidity may affect the bioavailability of cefuroxime. The beneficial effect of a meal on absorption of the drug may also be reversed.
- Cefuroxime affects the intestinal flora. Therefore, other drugs such as estrogens may be less readily absorbed and oral contraceptives may have a decreased effect. Similarly, there may be an increase in the International Normalized Ratio (INR) if oral blood thinners (anticoagulants) are given concomitantly with the antibiotic.
- When the agent is co-prescribed with probenecid, the maximum concentration of cefuroxime may increase significantly and the elimination half-life may be prolonged. Therefore, concomitant medication with the two agents is not recommended. The drug should also not be combined with other antibiotics such as tetracyclines, erythromycin, chloramphenicol, or sulfonamides because antagonistic and synergistic effects may occur with aminoglycosides.
- Since cefuroxime is excreted almost unchanged by the kidneys, renal function should be regularly checked and monitored if patients are taking parallel loop diuretics such as furosemide or etacrynic acid or potentially kidney-damaging drugs such as aminoglycoside antibiotics, polymyxin B and colistin are combined with the active substance. This also applies to elderly patients with impaired renal function.
