Imipenem/Cilastatina Kabi (Cilastatin Sodium, Imipenem Monohydrate)

Imipenem/cilastatin is a carbapenem antibiotic used to treat serious bacterial infections across several organ systems.

• Complicated intra‑abdominal infections: provides rapid bacterial clearance in patients with intra‑abdominal sepsis.
• Complicated urinary tract infections: eradicates resistant uropathogens causing pyelonephritis and cystitis.
• Skin and soft tissue infections: treats severe cellulitis, abscesses, and necrotizing infections.
• Febrile neutropenia: offers broad‑spectrum coverage for neutropenic patients with fever.
• Pneumonia: effective against hospital‑acquired and ventilator‑associated pneumonia.

• Imipenem binds to penicillin‑binding proteins on bacterial cell walls, inhibiting the final transpeptidation step of peptidoglycan synthesis, which leads to cell lysis. Cilastatin, co‑administered, inhibits renal dehydropeptidase‑I, preventing rapid degradation of imipenem and thereby increasing its plasma concentration and antibacterial activity. This dual action expands the spectrum to include many Gram‑negative, Gram‑positive and anaerobic organisms, including those resistant to other β‑lactams.

Adverse reactions to Imipenem/cilastatin may vary in frequency and severity.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Diarrhea: may be watery and self‑limiting.
• Rash: localized skin erythema.
• Elevated liver enzymes: transient increase in ALT/AST.
• Headache: mild discomfort.

Serious or Rare Side Effects

• Seizures: especially in patients with renal impairment or high doses.
• Anaphylaxis: acute, potentially life‑threatening hypersensitivity.
• Severe neutropenia: marked reduction in white blood cells.
• Clostridioides difficile colitis: antibiotic‑associated severe diarrhea.
• Stevens‑Johnson syndrome: rare mucocutaneous reaction.

Before prescribing Imipenem/cilastatin, clinicians should consider several safety precautions.

• Renal function: adjust dose in patients with impaired kidney function.
• History of seizures: avoid or monitor closely in individuals with prior seizure disorders.
• Allergies: contraindicated in patients with known hypersensitivity to β‑lactams.
• Concomitant valproic acid: monitor for decreased valproate levels and seizure risk.
• Pregnancy and lactation: use only if benefits outweigh potential risks, as safety data are limited.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Imipenem/cilastatin can interact with other medicines, affecting efficacy or safety.

Major Interactions (Avoid)

• Valproic acid: reduces valproate concentrations, increasing seizure risk.
• Carbapenem antibiotics with other β‑lactams: may cause antagonistic effects.
• Probenecid: may increase imipenem plasma levels, raising toxicity risk.

Moderate Interactions (Monitor Closely)

• Diuretics (e.g., furosemide): may enhance nephrotoxic potential.
• Anticoagulants (warfarin): monitor INR as imipenem may alter coagulation.
• CNS depressants: may potentiate seizure threshold lowering.