What is hydromorphone, and is it an alternative to Victoria's second injecting room?

Victoria will soon trial a new medication to try and help long-term users break their addiction. When Premier Jacinta Alan reneged on plans to set up a second safe injecting room in Melbourne this week. She committed to the trial of the pain killer Hydromorphone. Experts have welcomed it but are concerned about its small scope and the fact that it won’t begin for two years.