Imipenem/Cilastatin Aptapharma (Cilastatin, Imipenem)

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

• Complicated intra‑abdominal infections: effective bacterial eradication in patients with perforated or postoperative abdominal infections.
• Complicated urinary tract infections: clears resistant Gram‑negative pathogens in acute pyelonephritis and cystitis.
• Skin and soft tissue infections: treats severe cellulitis, necrotizing fasciitis, and infected wounds.
• Lower respiratory tract infections: combats pneumonia caused by multidrug‑resistant organisms.
• Febrile neutropenia: provides rapid coverage for high‑risk neutropenic patients with suspected bacterial sepsis.

• 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.

Imipenem/cilastatin may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Nausea: transient gastrointestinal discomfort.
• Diarrhea: may be mild to moderate.
• Headache: occasional dull or throbbing pain.
• Rash: erythematous skin eruption.
• Elevated liver enzymes: mild transaminase increase.
• Injection site reactions: pain or erythema at the infusion site.

Serious or Rare Side Effects

• Seizures: especially in patients with renal impairment or high doses.
• Anaphylaxis: severe allergic reaction with hypotension and airway compromise.
• Clostridioides difficile‑associated diarrhea: potentially life‑threatening colitis.
• Thrombocytopenia: marked reduction in platelet count.
• Acute renal impairment: sudden decrease in kidney function.
• Pseudomembranous colitis: inflammation of the colon due to toxin‑producing bacteria.

Use of Imipenem/cilastatin requires careful clinical assessment and monitoring.

• Renal function: adjust dose in patients with impaired renal clearance.
• Seizure risk: monitor patients with central nervous system disorders or receiving high doses.
• Allergy: avoid in individuals with known hypersensitivity to β‑lactam antibiotics.
• Drug interactions: review concomitant medications that may lower seizure threshold.
• Pregnancy and lactation: prescribe only when the potential benefit justifies the potential risk.
• Store at 2‑8°C: keep refrigerated, protect from light, do not freeze or shake.

Imipenem/cilastatin can interact with several medicines; clinicians should evaluate the relevance of each.

Major Interactions (Avoid)

• Valproic acid: may reduce serum levels, increasing seizure risk.
• Ganciclovir: antagonistic effect reducing antiviral efficacy.
• Probenecid: can raise imipenem concentrations, heightening toxicity.

Moderate Interactions (Monitor Closely)

• Diuretics: may alter renal clearance of the drug.
• Aminoglycosides: additive nephrotoxic potential.
• Anticonvulsants (e.g., phenobarbital): may lower seizure threshold when combined.