Imipenem with cilastatin and relebactam

How it works

Imipenem inhibits bacterial cell wall synthesis by binding penicillin-binding proteins, cilastatin blocks renal dehydropeptidase to protect imipenem from degradation, and relebactam inhibits key beta-lactamases to restore activity against resistant organisms.

Prescribing in practice

• Reserve this agent for confirmed or strongly suspected multidrug-resistant Gram-negative infection under specialist and microbiology guidance to preserve its activity.
• Imipenem lowers the seizure threshold, so use cautiously in patients with CNS disorders or renal impairment, and it markedly reduces valproate levels with risk of loss of seizure control.
• The dose requires adjustment in renal impairment, and there is potential for cross-reactivity in patients with severe penicillin allergy.

Monitoring

Monitor renal function to guide dosing and observe for neurological effects such as seizures, particularly in at-risk patients.

Counselling the patient

• This is a reserve antibiotic given in hospital for difficult-to-treat infections.
• Tell the team about any previous reactions to penicillins or carbapenems.
• Report any twitching, confusion or seizures promptly.

Evidence & guidelines

Imipenem-cilastatin-relebactam is positioned as a reserve antibiotic for resistant Gram-negative infections within antimicrobial stewardship frameworks.