Imipenem/Cilastatine Arrow (Cilastatin, Imipenem)

Imipenem/cilastatin is a broad‑spectrum carbapenem antibiotic used for serious bacterial infections.

• Complicated intra‑abdominal infections: provides bactericidal activity against the mixed flora involved, helping to resolve infection.
• Complicated urinary tract infections: eradicates resistant Gram‑negative and Gram‑positive pathogens, facilitating urinary tract clearance.
• Complicated skin and soft‑tissue infections: eliminates deep‑seated bacterial contamination, promoting wound healing.
• Nosocomial pneumonia: penetrates lung tissue to treat hospital‑acquired respiratory infections.
• Severe sepsis: offers rapid bacterial kill to support systemic infection control.

• 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 occur with imipenem/cilastatin therapy.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Vomiting: occasional emesis following infusion.
• Diarrhea: loose stools, may be self‑limiting.
• Rash: skin erythema or pruritus.
• Headache: transient cephalic discomfort.
• Elevated liver enzymes: mild transaminase increase.

Serious or Rare Side Effects

• Seizures: especially in patients with renal impairment or CNS disorders.
• Anaphylaxis: acute hypersensitivity reaction requiring emergency care.
• Clostridioides difficile‑associated diarrhea: severe colitis risk.
• Neutropenia: marked reduction in neutrophil count.
• Thrombocytopenia: low platelet levels leading to bleeding risk.
• Renal toxicity: worsening kidney function in susceptible individuals.

Careful assessment and monitoring are essential when using imipenem/cilastatin.

• Assess renal function: adjust dosing based on creatinine clearance.
• Monitor for seizures: avoid in patients with a history of epilepsy or CNS disease.
• Evaluate hypersensitivity: discontinue if signs of anaphylaxis appear.
• Use caution in hepatic impairment: watch liver enzyme trends.
• Adjust dose in renal impairment: follow renal dosing guidelines.
• Store at below 25°C: keep in the original pack, protect from moisture.

Imipenem/cilastatin may interact with other medicines, requiring attention to avoid reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Valproic acid: concomitant use can markedly lower valproate levels, risking seizure breakthrough.
• Probenecid: may decrease renal clearance of imipenem, increasing toxicity.
• Other carbapenems: combined use can amplify neurotoxicity.

Moderate Interactions (Monitor Closely)

• NSAIDs: may increase risk of CNS adverse effects such as seizures.
• Loop diuretics: can affect renal excretion, necessitating dose review.
• Anticoagulants (e.g., warfarin): may alter INR, requiring closer coagulation monitoring.