Imipenem/Cilastatina Hikma (Cilastatin Sodium, Imipenem Monohydrate)

Imipenem/Cilastatin is a carbapenem antibiotic indicated for severe bacterial infections affecting various organ systems.

• Complicated intra‑abdominal infections: provides rapid bacterial eradication to resolve intra‑abdominal sepsis.
• Complicated urinary tract infections: offers broad‑spectrum activity to treat resistant uropathogens.
• Nosocomial pneumonia (including ventilator‑associated pneumonia): delivers effective coverage against Gram‑negative and Gram‑positive pathogens in hospital‑acquired lung infections.
• Skin and soft‑tissue infections: offers potent activity for serious cellulitis and wound infections.
• Severe sepsis and septic shock: supplies critical antimicrobial support to improve outcomes in systemic infection.

• Imipenem exerts its antibacterial effect by binding to penicillin‑binding proteins, inhibiting the final stages of peptidoglycan cross‑linking and thereby disrupting bacterial cell‑wall synthesis. Cilastatin, co‑administered, inhibits renal dehydropeptidase I, preventing enzymatic degradation of imipenem and increasing its urinary concentration, which enhances overall antimicrobial exposure. This dual action results in a time‑dependent bactericidal activity against a wide range of Gram‑positive and Gram‑negative organisms, including many resistant strains.

The safety profile of Imipenem/Cilastatin includes both frequent and infrequent adverse reactions that clinicians monitor during therapy.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Diarrhea: may be watery and self‑limiting.
• Rash: skin erythema or pruritus.
• Elevated liver enzymes: transient increase in transaminases.
• Injection site pain: discomfort at the IV site.

Serious or Rare Side Effects

• Seizures: especially in patients with renal impairment or high doses.
• Anaphylaxis: severe allergic reaction requiring immediate intervention.
• Clostridioides difficile colitis: antibiotic‑associated intestinal infection.
• Neutropenia: marked reduction in white blood cell count.
• Renal dysfunction: worsening kidney function in susceptible individuals.

Prior to initiating Imipenem/Cilastatin therapy, healthcare providers should consider several precautionary measures to minimize risk.

• Renal function assessment: adjust dose in patients with impaired clearance.
• Seizure risk evaluation: avoid high doses in individuals with a history of seizures or CNS disorders.
• Allergy screening: confirm no known hypersensitivity to β‑lactam antibiotics or cilastatin.
• Concomitant nephrotoxic drugs: monitor closely when used with aminoglycosides or vancomycin.
• Electrolyte monitoring: watch for hypokalemia during prolonged therapy.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Imipenem/Cilastatin may interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Valproic acid: concomitant use can reduce valproate levels, risking seizure breakthrough.
• Carbapenem‑inducing agents: may increase risk of seizures when combined with high‑dose carbapenems.

Moderate Interactions (Monitor Closely)

• Aminoglycosides: additive nephrotoxicity; monitor renal function.
• Vancomycin: potential for increased nephrotoxic effect; assess kidney markers.
• Diuretics: may exacerbate electrolyte disturbances; check serum potassium.
• Oral contraceptives: possible reduction in hormonal efficacy; advise alternative contraception.