Adults

Usually 1-2 g once daily (or in two divided doses) IM or IV, depending on the severity of infection. Max 4 g/day.

Elderly

No specific dose adjustment typically required unless severe renal/hepatic impairment. Monitor closely.

Renal_impairment

No dose adjustment necessary for mild to moderate renal impairment. For severe impairment (creatinine clearance <10 mL/min), consider reducing dose to 500 mg to 1 g once daily. Hemodialysis and peritoneal dialysis do not remove significant amounts, no additional dose needed post-dialysis.

Onset

Rapid, typically within minutes after IV administration, or within hours after IM administration.

Excretion

Approximately 50-60% excreted unchanged in urine and 40-50% excreted via bile and feces.

Half life

Approximately 6-9 hours (longer in neonates and patients with severe hepatic or renal impairment).

Absorption

Rapidly and completely absorbed after intramuscular (IM) injection. Peak plasma concentrations are reached within 2-3 hours.

Metabolism

Mainly metabolized in the liver to inactive metabolites.

Aminoglycosides

May have synergistic antibacterial effects, but physical incompatibility in solution.

Calcium-containing solutions

Concomitant use in neonates is contraindicated due to precipitation risk.

Vaccines (e.g., Typhoid vaccine)

Antibiotics may reduce the therapeutic effect of live bacterial vaccines.

Loop diuretics (e.g., Furosemide)

May increase nephrotoxicity, especially with other nephrotoxic drugs.

Oral anticoagulants (e.g., Warfarin)

May increase anticoagulant effect; monitor INR.