What are these "anti-heroin implants" Pete Doherty has had installed?

[astro]

Re the linked article what are these things?

Doherty, who had a third set of anti-heroin implants fitted four months ago, vowed to become “George Best in reverse” by beating his addictions. But he failed to give a direct answer when asked if he still takes heroin.

“Well, if I am, there would be no point… all my opiate receptors are blocked,” he said.

He hinted that he still goes on drug binges, saying: “Well, the one time I really did push it … it wasn’t working so that was a relief.”

Doherty also denied claims he could be HIV-positive, like one of his former drug dealers, and revealed he had destroyed Kate’s love letters because he was terrified they would fall into the wrong hands.

[lexi]

I think it is the new Buprenorphine Implant - from studies - it seems to be an extremely effective treatment.

[CaveMike]

I never heard of this guy, so I did a Google search. Wikipedia indicates he uses/used a Naltrexone implant.

[Derleth]

A cursory glance through the Wikipedia article didn’t address this, so I’ll ask it here: What happens if someone on Naltrexone gets into a severe accident and needs immediate effective pain control? What if he needs an emergency operation? Don’t all really effective anaesthetics/analgesics bind to opiod receptors?

[Qadgop_the_Mercotan]

@Derleth

A cursory glance through the Wikipedia article didn’t address this, so I’ll ask it here: What happens if someone on Naltrexone gets into a severe accident and needs immediate effective pain control? What if he needs an emergency operation? Don’t all really effective anaesthetics/analgesics bind to opiod receptors?

Analgesics, yes. Anesthetics, less so.

But basically under controlled conditions, naltrexone can be over-ridden by a good anesthesiologist. As long as the anesthesiologist knows that naltrexone is on board.