Adults

The usual adult dosage is 200 mg once daily or 100 mg twice daily. For severe or persistent infections, the dose may be increased to 400 mg once daily or 200 mg twice daily.

Elderly

No specific dose adjustment is required for elderly patients unless there is severe renal impairment. Renal function should be monitored.

Renal_impairment

For patients with creatinine clearance between 21-60 mL/min or on hemodialysis, the dose should be reduced to 200 mg once daily. For creatinine clearance <20 mL/min, the dose should be 100 mg once daily.

Onset

Onset of antibacterial action typically occurs within 1-2 hours after oral administration.

Excretion

Approximately 50-55% of the absorbed dose is excreted unchanged in the urine over 24 hours. Renal excretion is the primary route.

Half life

The plasma half-life of cefixime is typically 3-4 hours, allowing for once or twice daily dosing.

Absorption

Oral bioavailability is 40-50%, and it is not significantly altered by food. Peak plasma concentrations are achieved within 2-6 hours after administration.

Metabolism

Cefixime undergoes limited metabolism in the liver; most of the absorbed drug is excreted unchanged.

Warfarin

Concurrent use may prolong prothrombin time (INR) with or without clinical bleeding. Close monitoring of coagulation parameters is advised.

Carbamazepine

Elevated carbamazepine levels have been reported when co-administered with cefixime. Monitor carbamazepine levels.

Oral Contraceptives

Some cephalosporins may reduce the efficacy of oral contraceptives, although this interaction is less commonly reported with cefixime.