Adults

200-400 mg every 8-12 hours by slow intravenous infusion over 30-60 minutes, depending on the type and severity of infection. Doses may be increased in severe cases.

Elderly

Dosage adjustment may be needed based on renal function.

Renal_impairment

Dose reduction is required based on creatinine clearance (e.g., CrCl 30-60 mL/min: max 400 mg every 12 hours; CrCl <30 mL/min: max 400 mg every 18-24 hours).

Onset

Rapid (within minutes after IV administration).

Excretion

Primarily via renal excretion (both glomerular filtration and tubular secretion), with some non-renal clearance.

Half life

3 to 5 hours (can be prolonged in renal impairment).

Absorption

Rapid and complete systemic absorption (100% bioavailability) after intravenous administration. Peak plasma concentrations are achieved at the end of infusion.

Metabolism

Partially metabolized in the liver to less active metabolites.

Warfarin

Enhanced anticoagulant effects (monitor INR/PT).

Tizanidine

Increased tizanidine plasma concentrations, leading to hypotension and somnolence (contraindicated).

Cyclosporine

Increased serum creatinine and potential nephrotoxicity.

Methotrexate

Increased methotrexate plasma levels and potential toxicity.

Theophylline

Increased theophylline levels and toxicity (monitor levels).