Imipenem/Cilastatin Noridem (Cilastatin, Imipenem)

Imipenem/Cilastatin is a broad‑spectrum carbapenem antibiotic used for serious bacterial infections affecting various organ systems.

• Complicated intra‑abdominal infections: provides bactericidal activity to resolve infection.
• Complicated urinary tract infections: eradicates uropathogens resistant to other agents.
• Nosocomial pneumonia: treats hospital‑acquired lung infection caused by Gram‑negative and Gram‑positive bacteria.
• Severe skin and soft‑tissue infections: combats mixed flora in deep tissue infections.
• Sepsis and septic shock: delivers rapid bacterial clearance in systemic infection.

• Imipenem binds to penicillin‑binding proteins, inhibiting the final transpeptidation step of bacterial cell‑wall synthesis, leading to cell lysis. Cilastatin, co‑administered, inhibits renal dehydropeptidase I, preventing enzymatic degradation of imipenem in the kidneys and thereby extending its antibacterial activity.

Adverse reactions may occur with any antimicrobial therapy and should be monitored.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Vomiting: occasional emesis following infusion.
• Diarrhea: may be self‑limiting or indicate colitis.
• Headache: transient cranial discomfort.
• Infusion site phlebitis: irritation at the intravenous site.
• Elevated liver enzymes: transient increase in hepatic transaminases.

Serious or Rare Side Effects

• Seizures: especially in patients with renal impairment or CNS disorders.
• Anaphylaxis: acute hypersensitivity reaction requiring immediate treatment.
• Clostridioides difficile‑associated diarrhea: severe colitis risk.
• Severe neutropenia: marked reduction in white blood cells.
• Renal dysfunction: worsening kidney function in susceptible individuals.
• Stevens‑Johnson syndrome: rare but life‑threatening skin reaction.

Careful assessment and monitoring are required when using this intravenous antibiotic.

• Renal function assessment: adjust dosing in patients with impaired kidneys.
• Hepatic function monitoring: observe liver enzyme levels during therapy.
• Allergy history: avoid in individuals with known carbapenem hypersensitivity.
• Concomitant valproic acid: monitor for decreased anticonvulsant levels.
• Pregnancy: use only if the potential benefit justifies the potential risk to the fetus.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Imipenem/Cilastatin may interact with several concomitant medications.

Major Interactions (Avoid)

• Valproic acid: reduces plasma concentrations, risking seizure breakthrough.
• Warfarin: may increase INR and bleeding risk.
• Probenecid: decreases renal excretion, potentially lowering efficacy.

Moderate Interactions (Monitor Closely)

• Diuretics: heightened risk of electrolyte imbalance.
• Aminoglycosides: additive nephrotoxicity potential.
• Rifampin: induces metabolism, possibly reducing drug levels.