Adults

General dosage: 500 mg to 1 g, once or twice daily, depending on the severity and type of infection. For most infections, 1 g once daily or 500 mg twice daily is common. For pharyngitis/tonsillitis, 1 g once daily for 10 days.

Elderly

Dosage adjustment may be needed based on renal function due to age-related decline in kidney function. Monitor creatinine clearance.

Renal_impairment

Initial dose is 1 g. Subsequent doses and intervals should be adjusted based on creatinine clearance: CrCl 50 mL/min: 500 mg every 12 hours; CrCl 25 mL/min: 500 mg every 24 hours; CrCl 10 mL/min: 500 mg every 36 hours; CrCl < 10 mL/min: 500 mg every 48 hours.

Onset

Approximately 1-2 hours for significant antibacterial effect.

Excretion

Primarily excreted unchanged in the urine by glomerular filtration and tubular secretion. Approximately 90% of the dose is excreted within 24 hours.

Half life

The plasma elimination half-life is approximately 1 to 2 hours in individuals with normal renal function.

Absorption

Well absorbed from the gastrointestinal (GI) tract after oral administration. Peak plasma concentrations are reached approximately 1-2 hours after dosing.

Metabolism

Cefadroxil is minimally metabolized in the liver.

Probenecid

May increase cefadroxil plasma concentrations by decreasing its renal tubular secretion, potentially leading to higher and more prolonged levels.

Oral anticoagulants

Cefadroxil may enhance the anticoagulant effect of warfarin and other oral anticoagulants, requiring monitoring of INR and possible dose adjustment.

Loop diuretics (e.g., Furosemide)

Concomitant use with high doses of loop diuretics may increase the risk of nephrotoxicity, particularly in patients with pre-existing renal impairment.