Adults

250-500 mg every 6 hours, usually taken 30-60 minutes before meals. For severe infections, dose may be increased.

Children

12.5-25 mg/kg body weight every 6 hours, or as directed by physician. Maximum daily dose should not exceed adult dose.

Renal_impairment

Dose reduction may be necessary in severe renal impairment (creatinine clearance < 10 ml/min). No adjustment usually needed for mild to moderate impairment.

Onset

Clinical improvement often observed within 24-48 hours of initiating therapy.

Excretion

Primarily excreted unchanged by the kidneys via tubular secretion and glomerular filtration, with some biliary excretion.

Half life

Approximately 0.5-1.5 hours in adults with normal renal function, increasing in renal impairment.

Absorption

Rapidly absorbed after oral administration, though food significantly reduces absorption. Peak plasma concentrations are typically reached within 1-2 hours.

Metabolism

Partially metabolized in the liver to active and inactive metabolites.

Warfarin

May potentiate the anticoagulant effect, necessitating close monitoring of INR and possible dose adjustment of warfarin.

Methotrexate

Cloxacillin may reduce renal clearance of methotrexate, potentially increasing methotrexate levels and toxicity. Monitor closely.

Aminoglycosides

Physical and chemical inactivation can occur if cloxacillin and aminoglycosides are mixed in vitro; administer separately.

Oral Contraceptives

May reduce the efficacy of oral contraceptives; advise patients to use alternative or additional birth control methods.