[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Carbapenems](https://durgical.com/en/pharmacology/classes/carbapenems/) › Imipenem–cilastatin [Pharmacology](https://durgical.com/en/pharmacology/) · [Carbapenems](https://durgical.com/en/pharmacology/classes/carbapenems/) # Imipenem–cilastatin A very broad carbapenem paired with cilastatin, which stops the kidney from destroying it; it carries the highest seizure risk of its class. Updated 2026-11-01 - Class: [Carbapenems](https://durgical.com/en/pharmacology/classes/carbapenems/) - Enzyme: Penicillin-binding proteins (bacterial transpeptidases) - ATC code: J01DH51 ✂**Penicillin-binding proteins (bacterial transpeptidases)**Imipenem–cilastatin ⓘ The figure shows imipenem bound to penicillin-binding protein 3 of Pseudomonas aeruginosa (cilastatin acts on a human kidney enzyme and is not in the structure). **Target in 3D:** Penicillin-binding proteins (bacterial transpeptidases). PDB structure 3PBQ (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/3PBQ) · Drag to rotate · pinch to zoom ## Mechanism of action Imipenem binds many penicillin-binding proteins, with the lethal effect linked to PBP2 and PBP1B, and stops cell-wall cross-linking. On its own it would be hydrolysed by dehydropeptidase I in the brush border of the proximal tubule; cilastatin blocks that enzyme, so imipenem lasts longer and reaches the urine in active form. - Imipenem acylates PBPs and stops wall cross-linking - Cilastatin blocks renal dehydropeptidase I - Imipenem stays active longer, also in urine - The bacterial wall fails and the cell lyses ## Pharmacokinetics **Absorption** Intravenous only; not absorbed by mouth. **Metabolism** Without cilastatin, imipenem is hydrolysed in the proximal tubule; cilastatin prevents this. **Elimination** Through the kidney; about 70% of imipenem appears in the urine as active drug when given with cilastatin. **Half-life** About 1 hour for each component. ## Indications - Lower respiratory tract infections, including hospital-acquired pneumonia by resistant organisms. [Hospital-acquired and ventilator-associated pneumonia →](https://durgical.com/en/conditions/hospital-acquired-and-ventilator-associated-pneumonia/) - Complicated and uncomplicated urinary tract infections. [Acute pyelonephritis →](https://durgical.com/en/conditions/acute-pyelonephritis/) - Intra-abdominal infections. [Peritonitis →](https://durgical.com/en/conditions/peritonitis/) - Bone and joint infections, skin infections, septicemia and endocarditis by susceptible bacteria. [Osteomyelitis →](https://durgical.com/en/conditions/osteomyelitis/) ## Adverse effects ### Common - Phlebitis and pain at the infusion site - Nausea, vomiting, diarrhoea - Rash, itching, fever, hypotension, dizziness, somnolence ### Serious (rare, important) - Seizures, confusion and myoclonus, more likely with kidney failure, CNS lesions or high doses - Anaphylaxis - Clostridioides difficile diarrhoea ## Contraindications - Hypersensitivity to any component - Not used for meningitis (efficacy and safety not established; seizure risk) ## Key interactions **Valproic acid / divalproex** Valproate falls and breakthrough seizures can occur; generally avoided. **Ganciclovir** Generalized seizures reported; given together only if the benefit outweighs the risk. **Probenecid** Raises imipenem levels and half-life; not recommended. ## What is monitored - Kidney function; the regimen is adjusted to creatinine clearance - Neurological status: tremor, myoclonus, seizures - Signs of allergy and of C. difficile diarrhoea ## Administration and safety - Reconstituted and diluted before IV infusion; not given as a bolus. - Nausea during the infusion often settles by slowing it, as ordered. - Check that the product ordered is imipenem–cilastatin and not the version with relebactam or another carbapenem. ## Nursing care - Ask about β-lactam allergy, epilepsy and valproic acid before the first dose. - Seizure precautions in patients with kidney failure or brain lesions. - Inspect the IV site for phlebitis. - Teaching: report twitching, confusion, rash or severe diarrhoea. ## Pregnancy and breastfeeding A small number of human cases do not show a clear risk, and animal studies showed no malformations; it is used in pregnancy when clearly needed. ## Memory aid «Imipenem needs its CILAstatin bodyguard to get past the kidney»; and «IMIpenem IMItates epilepsy» (most seizures of the class). ## Test yourself Think of the answer, then tap the question to see it. ## What would happen to imipenem without cilastatin? Dehydropeptidase I in the proximal tubule would hydrolyse it, shortening its action and lowering active drug in the urine. ## Which patients are at highest risk of imipenem seizures? Those with kidney failure, brain lesions or a seizure history, and those on high doses; children with CNS infection should not receive it. ## Which antiviral increases seizure risk when combined with imipenem? Ganciclovir; generalized seizures have been reported with the combination. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/imipenem-cilastatin/) ## Related drugs - [Meropenem](https://durgical.com/en/pharmacology/meropenem/) - [Ertapenem](https://durgical.com/en/pharmacology/ertapenem/) - [Valproic acid](https://durgical.com/en/pharmacology/valproic-acid/) ## Related conditions - [Hospital-acquired and ventilator-associated pneumonia](https://durgical.com/en/conditions/hospital-acquired-and-ventilator-associated-pneumonia/) - [Acute pyelonephritis](https://durgical.com/en/conditions/acute-pyelonephritis/) - [Peritonitis](https://durgical.com/en/conditions/peritonitis/) - [Osteomyelitis](https://durgical.com/en/conditions/osteomyelitis/) [← Back to the class: Carbapenems](https://durgical.com/en/pharmacology/classes/carbapenems/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - IMIPENEM AND CILASTATIN- imipenem and cilastatin sodium injection, powder, for solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6ab0ca9e-9a79-4cab-9f09-470eda06952e) (DailyMed (U.S. National Library of Medicine), 2026); [Imipenem and Cilastatin Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a686013.html) (MedlinePlus (U.S. National Library of Medicine), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 58 (McGraw Hill, 2023); [RCSB PDB - 3PBQ: Crystal structure of PBP3 complexed with imipenem](https://www.rcsb.org/structure/3PBQ) (RCSB Protein Data Bank, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/imipenem-cilastatin/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/imipenem-cilastatin/