Addicts who were using prescription heroin as part of a clinical trial in Vancouver have won a temporary injunction to continue getting the drug.
It's the second time in recent months that courts have interfered with a federal government attempt to rein in the medical use of otherwise illegal drugs.
Five people filed a lawsuit last fall alleging the federal government is violating their charter rights by denying them access to prescription heroin to treat their addictions.
Those patients received the heroin during a clinical trial, but once they left the trial last year, their doctors asked for special federal approval to continue prescribing the drug.
Health Canada initially granted those approvals, but Health Minister Rona Ambrose responded by changing regulations to stop such approvals and the patients have not received any more prescription heroin.
A BC Supreme Court judge has now issued an injunction exempting the patients from the updated regulations while the court case proceeds.
"These potential harms are clearly irreparable in nature," Justice Christopher Hinkson wrote in a decision granting the injunction.
"I accept that the potential harms facing the personal plaintiffs, and those on whose behalf they apply, are grave and that an award of damages will be of little, if any, assistance to them."
The plaintiffs in the case all took part in clinical trials conducted by Providence Health Care, which operates St. Paul's Hospital in downtown Vancouver.
The first trial, the North American Opiate Medication Initiative, or NAOMI, took place in Vancouver and Montreal from March 2005 to July 2008. The blind study compared the effectiveness of pharmaceutical-grade heroin, known as diacetylmorphine, and oral methadone. Two of the plaintiffs were NAOMI participants.
The second trial, the Study to Assess Longer-term Opioid Medication Effectiveness, or SALOME, began in 2011. The study is comparing the effectiveness of hydromorphone, a synthetic drug approved for use to control pain, and pharmaceutical heroin in treating severe addiction. All five plaintiffs took part, exiting the program last year.
Doctors applied to Health Canada for special permission to prescribe heroin to 21 people, including the five plaintiffs, after they finished participating in the study.
However, Ambrose said the program under which the approvals were granted was never intended to allow doctors to prescribe illegal drugs. She has suggested prescribing heroin amounts to giving up on addicts.
A spokesperson for Health Canada wasn't immediately available for comment.