Adults

The usual adult dose is 400 mg orally once daily, or 200 mg every 12 hours. Duration depends on the infection and may range from 3 to 14 days.

Elderly

No specific dose adjustment is required in elderly patients with normal renal function; however, renal function should be monitored, and dose adjusted if impairment is present.

Renal_impairment

For creatinine clearance 21-60 mL/min, the dose should be reduced to 300 mg daily. For creatinine clearance < 20 mL/min, the dose should be 200 mg daily.

Onset

Clinical effect typically observed within 24-48 hours of initiation.

Excretion

Approximately 50% of an absorbed dose is excreted unchanged in the urine over 24 hours. Some biliary excretion also occurs. Renal impairment prolongs half-life.

Half life

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

Absorption

Oral absorption is about 40-50%, not significantly affected by food. Peak plasma concentrations are achieved 2-6 hours after administration.

Metabolism

Cefixime is not extensively metabolized; about 10% may be metabolized. No active metabolites are formed.

Probenecid

May increase cefixime plasma concentrations by inhibiting its renal excretion.

Carbamazepine

Concomitant administration has been shown to result in increased carbamazepine levels.

Warfarin and other anticoagulants

Increased prothrombin time (INR) with concomitant use; monitoring of coagulation parameters is recommended to adjust anticoagulant dose if necessary.