Imipenem/Cilastatin Fresenius Kabi (Cilastatin Sodium, Imipenem Monohydrate)

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

• Complicated intra‑abdominal infections: provides rapid bacterial eradication in severe abdominal sepsis.
• Complicated urinary tract infections: eliminates resistant uropathogens in hospitalized patients.
• Skin and soft tissue infections: treats deep‑seated or necrotizing infections caused by Gram‑negative and Gram‑positive organisms.
• Nosocomial pneumonia: covers multidrug‑resistant pathogens in ventilated patients.
• Septicemia: delivers systemic antibacterial activity for bloodstream infections.

• Imipenem binds to penicillin‑binding proteins, inhibiting the final stages of bacterial cell‑wall peptidoglycan synthesis, which leads to cell lysis. Cilastatin, co‑administered, blocks renal dehydropeptidase I, preventing enzymatic degradation of imipenem and thereby extending its plasma concentration and antibacterial activity.

Adverse reactions may range from mild to severe and should be monitored during therapy.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Diarrhea: may be watery or loose.
• Rash: erythematous skin eruption.
• Injection site pain: localized discomfort at the IV site.
• Elevated liver enzymes: transient increase in hepatic transaminases.
• Headache: mild to moderate intensity.

Serious or Rare Side Effects

• Seizures: especially in patients with renal impairment or CNS disorders.
• Anaphylaxis: acute, life‑threatening hypersensitivity reaction.
• Clostridioides difficile colitis: severe diarrhea due to gut flora disruption.
• Severe neutropenia: marked reduction in white blood cells.
• Renal toxicity: worsening kidney function in susceptible individuals.
• Stevens‑Johnson syndrome: rare severe mucocutaneous reaction.

Careful assessment is required before initiating therapy to minimize risks.

• Renal impairment: adjust dose or monitor renal function closely.
• Hypersensitivity: avoid in patients with known allergy to carbapenems or β‑lactams.
• Seizure risk: use cautiously in patients with CNS disorders or a history of seizures.
• Neonates and infants: limit use to approved indications and monitor closely.
• Pregnancy and lactation: safety not established; weigh benefits against potential risks.
• Store at 2‑8 °C: keep refrigerated, protect from light, do not freeze or shake.

Drug interactions can affect efficacy or increase toxicity and should be evaluated.

Major Interactions (Avoid)

• Valproic acid: carbapenems reduce serum valproate levels, risking seizure breakthrough.
• Warfarin: may enhance anticoagulant effect, increasing INR and bleeding risk.
• Nephrotoxic agents (e.g., aminoglycosides): combined use can exacerbate renal dysfunction.

Moderate Interactions (Monitor Closely)

• Diuretics: may potentiate electrolyte disturbances, especially potassium loss.
• Probenecid: can alter renal clearance of imipenem, requiring dose adjustment.
• Other β‑lactam antibiotics: concurrent use may increase risk of additive toxicity.