Diamorphine treatment for opiate dependence: putative markers of concomitant heroin misuse.

The supply of substitute opioid medication as a treatment for heroin dependence is now common practice. There is growing international interest in the prescription of injectable diamorphine for subgroups of patients who are unable to stop injecting opiate drugs; in the United Kingdom it is estimated that there are currently 300 patients prescribed diamorphine for this purpose. The detection of illicit heroin misuse (through urinary diamorphine metabolites) is confounded in subjects prescribed diamorphine.