In chronic opioid abusers, sedation and analgesia present challenges. We describe two trauma patients with naltrexone implants (depot micro-receptor antagonists that facilitate opioid withdrawal) requiring intensive care. The first patient, a 28-year-old man, sustained chest and pelvic injuries when hit by a motor vehicle. When we learned of the implant he was already on a morphine infusion, appearing responsive to it. It subsequently emerged that the implant was placed 3 months earlier, but had only a 6-week duration of effect and had expired. His intensive care course was unaffected. The second patient, a 24-year-old man, had been stabbed in the chest. His implant being recently placed, he was markedly opioid insensitive. Propofol, tramadol and paracetamol proved effective. We wish to notify colleagues of the existence of these implants as they are increasingly widely used, and should be considered when encountering severe opioid resistance. Secondly, their role in managing opioid-dependent physicians appears promising.