Adults

The usual adult dose is 200-400 mg daily, given as a single dose or in two divided doses (e.g., 200 mg every 12 hours). For uncomplicated gonorrhea, a single oral dose of 400 mg is recommended.

Elderly

No dosage adjustment is generally required for elderly patients unless there is significant renal impairment. Monitor renal function.

Renal_impairment

For patients with creatinine clearance less than 60 mL/min, the dose should be reduced. For creatinine clearance 21-60 mL/min, 75% of the standard dose; for less than 20 mL/min, 50% of the standard dose. Hemodialysis or peritoneal dialysis patients should receive 50% of the standard dose.

Onset

Peak plasma concentrations are achieved 2-6 hours after oral administration.

Excretion

Excreted primarily by the kidneys, with about 50% of the absorbed dose excreted unchanged in the urine over 24 hours. Biliary excretion is a minor route.

Half life

The plasma elimination half-life is typically 3-4 hours, but may be prolonged in patients with renal impairment.

Absorption

Approximately 40-50% orally absorbed. Food slightly prolongs absorption time but does not significantly affect the extent of absorption.

Metabolism

Cefixime is not extensively metabolized in the body; it is thought to be primarily eliminated as the unchanged drug.

Nifedipine

May increase Cefixime peak plasma levels and AUC, though clinical significance is usually minimal.

Carbamazepine

Concomitant administration with Cefixime has been shown to increase carbamazepine levels.

Oral Contraceptives

Cefixime may reduce the efficacy of oral contraceptives in some cases, although this interaction is not consistently proven. Advise patients to use an additional method of contraception.

Anticoagulants (e.g., Warfarin)

May increase prothrombin time, potentially leading to increased bleeding risk. Close monitoring of INR is recommended.