Adults

Not typically used in suspension form for adults, but 250-1000 mg every 6-12 hours for adults, based on infection severity.

Elderly

Similar to adult dosage; however, renal function should be assessed and dosage adjusted if necessary.

Renal_impairment

Dosage adjustment is necessary in patients with impaired renal function (e.g., CrCl < 20 mL/min, interval extension or dose reduction).

Onset

Therapeutic effects typically begin within an hour of administration.

Excretion

Primarily excreted unchanged in the urine by glomerular filtration and tubular secretion, with about 80% or more of the dose eliminated within 6 hours.

Half life

The elimination half-life is approximately 0.5-1.2 hours in individuals with normal renal function, increasing in renal impairment.

Absorption

Rapidly and almost completely absorbed from the gastrointestinal tract after oral administration. Peak plasma concentrations are usually achieved within 1-2 hours.

Metabolism

Cephalexin is not significantly metabolized in the liver.

Metformin

Cephalexin may increase the plasma concentration of metformin, requiring dose adjustment of metformin.

Probenecid

Concomitant administration of probenecid delays the renal excretion of cephalexin, leading to higher and more prolonged plasma concentrations.

Oral Anticoagulants

Rarely, cephalexin may enhance the anticoagulant effect of warfarin or other oral anticoagulants, increasing the risk of bleeding.