In Switzerland, as in many other European countries, heroin is prescribed to addicts as a form of treatment.
Zurich - Europe's financial capital, and Switzerland's largest city - had one of the largest open drug scenes in Europe. In the mid-90s the government approved 'heroin assisted treatment', the prescription of heroin to addicts, to try and combat the problem.
It worked. The death rate among heroin addicts in Switzerland has decreased to less than one per cent. Heroin Assisted Treatment has been credited with improving the mental and physical health of addicts, reducing crime and undermining the illegal heroin market.
Now there are calls to introduce it here in the South West. But it's highly controversial.
Dr Thilo Beck, who runs Arud Centre for Addiction Medicine - one of 23 heroin assisted treatment clinics in Switzerland - says the introduction of the programmes marked a decrease in the number of heroin users in the country, and improved the health of those in treatment.
Andy - who's been in heroin-assisted treatment for two years - says his life is now relatively normal.
He can inject safely, and is prescribed a dose that keeps him stable. He had just injected when we interviewed him. He has friends and a home.
He says he wouldn't go back to illegal drug taking, but can't see a future without heroin either.
For doctors here, the aim is not to wean people off heroin - often referred to as the most addictive substance in the world. Instead, they hope to give them a stable life and reintroduce them to society.
That ideology raises questions - with many arguing that heroin assisted treatment is a step towards the legalisation of drugs.
For it to work in Bristol there would need to be a joined up effort including the police, the local authority and the NHS.
Heroin assisted treatment clinics are expensive to set up, and while evidence from countries like Switzerland shows that it saves money long term, it's an obstacle here in the UK.