Imipenem Cilastatine Sun (Cilastatin Sodium, Imipenem Monohydrate)

• Imipenem/cilastatin is a broad‑spectrum carbapenem used for serious bacterial infections across several organ systems.
• Complicated intra‑abdominal infections: eradicates mixed aerobic and anaerobic pathogens and reduces morbidity.
• Complicated urinary tract infections: provides rapid bacterial clearance in resistant Gram‑negative infections.
• Skin and soft‑tissue infections: treats severe cellulitis and necrotizing infections caused by susceptible organisms.
• Community‑acquired and hospital‑acquired bacterial pneumonia: offers coverage against resistant Streptococcus pneumoniae and Gram‑negative pathogens.
• Septicemia: delivers bactericidal activity in bloodstream infections caused by susceptible bacteria.

• Imipenem binds to penicillin‑binding proteins, inhibiting the final stages of bacterial cell‑wall peptidoglycan synthesis, which leads to cell lysis. Cilastatin, co‑administered as a renal dehydropeptidase I inhibitor, prevents enzymatic degradation of imipenem in the kidneys, thereby maintaining therapeutic plasma concentrations.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Diarrhea: may be watery and self‑limiting.
• Vomiting: occasional episodes after infusion.
• Headache: transient and usually resolves.
• Rash: mild skin erythema or pruritus.
• Elevated liver enzymes: transient increase in hepatic transaminases.

Serious or Rare Side Effects

• Seizures: especially in patients with renal impairment or CNS disorders.
• Severe allergic reactions: anaphylaxis, angioedema, or Stevens‑Johnson syndrome.
• Clostridioides difficile colitis: antibiotic‑associated diarrhea that can be severe.
• Thrombophlebitis: inflammation at the infusion site.
• Renal toxicity: rare acute kidney injury.
• Hematologic abnormalities: neutropenia or thrombocytopenia.

Before initiating therapy, consider the following precautions:

• Renal function: adjust dosage in patients with impaired renal clearance.
• Allergy: avoid in individuals with known hypersensitivity to carbapenems or β‑lactams.
• Seizure risk: monitor closely in patients with a history of seizures or CNS disorders.
• Drug interactions: review concomitant medications that may lower seizure threshold.
• Pregnancy: use only if the potential benefit justifies the potential risk to the fetus.
• Store at below 25°C: keep in the original container, protect from moisture and light.

Imipenem/cilastatin may interact with several drugs; monitoring is advised.

Major Interactions (Avoid)

• Valproic acid: co‑administration can reduce valproate levels, increasing seizure risk.
• Cytotoxic chemotherapy agents: may potentiate neurotoxicity when given together.

Moderate Interactions (Monitor Closely)

• Diuretics (e.g., furosemide): may increase the risk of nephrotoxicity.
• Probenecid: can raise plasma concentrations of imipenem.
• Antacids containing magnesium or aluminum: may affect infusion site tolerance, though impact is minimal with IV administration.