Adults

Typical dose is 500 mg to 1 gm IV every 8 hours, or 2 gm IV every 8 hours for very severe infections. Dosage should be adjusted based on infection type, severity, and susceptibility of the pathogen.

Elderly

Dosage adjustment is usually not required in elderly patients with normal renal function. For those with impaired renal function, dosage should be adjusted as for renal impairment.

Renal_impairment

Dose reduction is necessary based on creatinine clearance (e.g., for CrCl 26-50 mL/min, 500 mg or 1 gm every 12 hours; for CrCl 10-25 mL/min, 250 mg or 500 mg every 12 hours).

Onset

Rapid, typically within minutes after IV administration.

Excretion

Primarily renal, with approximately 70% of the administered dose excreted unchanged in urine within 12 hours.

Half life

Approximately 1 hour in adults with normal renal function.

Absorption

Rapid and complete after intravenous administration.

Metabolism

Minimally metabolized; primarily by hydrolysis of the beta-lactam ring to an inactive metabolite.

Probenecid

Probenecid competes with meropenem for active tubular secretion, resulting in increased plasma concentrations and a prolonged half-life of meropenem. Co-administration is not recommended unless clinically justified.

Valproic Acid

Co-administration with meropenem can significantly decrease valproic acid plasma concentrations, potentially leading to subtherapeutic levels and increased risk of seizures. Concurrent use should generally be avoided.