Meropenem (Multi-resistant Gram-negative Bone Infections)

How it works

It binds penicillin-binding proteins to inhibit bacterial cell-wall peptidoglycan synthesis, and its stability against many beta-lactamases (including extended-spectrum and AmpC enzymes) underlies its activity against resistant Gram-negative bacilli.

Prescribing in practice

• Reserve for confirmed or strongly suspected multi-resistant Gram-negative bone infection on microbiology and antimicrobial-stewardship advice, as carbapenem overuse drives carbapenemase emergence.
• Lowers the seizure threshold, so use cautiously in patients with CNS disorders or epilepsy and review the dose in renal impairment.
• Co-administration reduces valproate levels and can precipitate seizures, so avoid the combination where possible.

Monitoring

Monitor renal function, inflammatory markers and clinical response over prolonged courses, with neurological review if confusion or seizures emerge.

Counselling the patient

• Report any rash, new confusion, or seizure activity promptly.
• Diarrhoea during or after treatment may indicate C. difficile and should be reported.
• Complete the full prescribed course even once feeling better.

Evidence & guidelines

UK antimicrobial-stewardship and bone and joint infection guidance supports reserving carbapenems for resistant organisms confirmed on culture.