Imipenem/Cilastatin Kabi (Cilastatin Sodium, Imipenem Monohydrate)

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

• Complicated intra‑abdominal infections: provides effective bacterial eradication in patients with severe abdominal sepsis.
• Complicated urinary tract infections: eliminates resistant uropathogens in complicated cystitis and pyelonephritis.
• Lower respiratory tract infections: treats hospital‑acquired pneumonia and ventilator‑associated lung infections.
• Skin and soft‑tissue infections: clears deep tissue infections caused by susceptible organisms.
• Febrile neutropenia: offers rapid coverage for neutropenic patients at risk of bacteremia.
• Meningitis caused by susceptible organisms: penetrates the cerebrospinal fluid to treat bacterial meningitis.

• Imipenem binds to penicillin‑binding proteins, inhibiting bacterial cell‑wall synthesis and leading to cell lysis. Cilastatin, co‑administered, blocks renal dehydropeptidase I, preventing enzymatic degradation of imipenem and thereby maintaining therapeutic plasma concentrations.

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

Common Side Effects

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

Serious or Rare Side Effects

• Seizures: especially in patients with pre‑existing CNS disorders.
• Anaphylaxis: severe, potentially life‑threatening allergic reaction.
• Clostridioides difficile‑associated diarrhea: severe colitis risk.
• Severe hypersensitivity reactions: including Stevens‑Johnson syndrome.
• Renal impairment: acute kidney injury in susceptible individuals.
• Hematologic abnormalities: neutropenia or thrombocytopenia.

Careful assessment and monitoring are required before and during therapy.

• Renal function monitoring: assess creatinine clearance and adjust dose as needed.
• Dose adjustment in renal impairment: reduce dosage or extend interval for patients with decreased kidney function.
• Seizure risk: avoid in patients with a history of seizures or CNS disorders.
• Hypersensitivity: do not use in individuals with known allergy to carbapenems or β‑lactams.
• Superinfection watch: monitor for secondary infections such as fungal overgrowth.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Imipenem/cilastatin may interact with other medicines, altering efficacy or safety.

Major Interactions (Avoid)

• Valproic acid: concomitant use can markedly reduce valproate levels, increasing seizure risk.
• Nephrotoxic agents (e.g., aminoglycosides, amphotericin B): combined use may exacerbate renal toxicity.
• Other carbapenems: concurrent therapy can increase toxicity without added benefit.

Moderate Interactions (Monitor Closely)

• Diuretics: may enhance renal clearance, requiring dose reassessment.
• NSAIDs: can affect renal function, necessitating closer monitoring.
• Anticoagulants (e.g., warfarin): may alter INR, requiring periodic coagulation checks.
• Probenecid: may increase plasma concentrations, warranting observation for toxicity.