The UK says it does not "park" heroin addicts on methadone as the Republic does - some people here have been on the heroin substitute for as long as 20 years.
Some drug treatment centres in the UK also take mouth swabs to detect if people receiving methadone are taking other illegal drugs. If they are detected the patient's methadone treatment is stopped - unlike here.
The Republic still uses urine samples for testing, which can be easily subverted by addicts buying other people's "clean" urine to avoid detection.
Kate Egan, a recovery practitioner dealing with heroin and crack addicts in the UK, was critical of the Republic's failures in dealing with addiction.
"The practice of parking a client on methadone is viewed as poor practice, and we always encourage and support reduction at a realistic and manageable amount, which will vary from client to client.
Source: Irish Independent, 10/08/14