Only one clinic in North America currently gives patients access to the drug.

The Canadian government tweaked its drug laws this month to allow doctors to prescribe medical-grade heroin to patients for whom other addiction treatments have failed.

Health Canada says the rule change is about battling "an opioid overdose crisis" and giving doctors another option for helping patients who continue to relapse.

Governments across Canada have been alarmed by a rise in overdose deaths, with many linked to fentanyl, the cheap and incredibly powerful synthetic opioid increasingly mixed in with cocaine, heroin, and other street drugs. Earlier this year, British Columbia's chief health officer declared a public health emergency after 200 fentanyl-related deaths in the province in only three months.

Under Health Canada's new rules, doctors can now get access to diacetylmorphine, as medical-grade heroin is known, under a special program. The rule change reverses a restriction put in place by the previous Conservative government, which reclassified heroin as a "restricted drug" in 2013 and made it inaccessible as a treatment option.

Health Canada says it received "no comments of opposition" to the change when it sought public input earlier this year.

Scott MacDonald, the lead physician at Providence Health Care’s Crosstown Clinic in Vancouver, said he welcomed the decision.

"It’s an important step forward for the treatment of severe opioid use disorder, particularly in light of the national crisis that we’re facing with opioids and fentanyl," he told BuzzFeed News.

Crosstown is the only clinic in North America to prescribe heroin to patients — and the clinic launched a court challenge in 2013 to maintain the program. Patients come in two or three times a day for their dose of heroin or morphine, which they take under medical supervision. While there, they also get access to social workers, counseling, and other support to help them get on their feet, MacDonald said.

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"The effect of fentanyl and overdoses is spreading, and still this clinic is the only one of its type," he said. "We need more clinics like this across the continent.”

The clinic says it has gotten visits from mayors in the US who are dealing with opioid crises in their own cities, including Seattle and Ithaca, New York. MacDonald also spoke to the US Senate Committee on Homeland Security and Governmental Affairs earlier this summer.

A number of other countries already prescribe heroin to treat opioid dependance, including Switzerland, Germany, the Netherlands, and Denmark. According to Health Canada, "there is a body of scientific evidence supporting its use as a treatment option for opioid addicts who have repeatedly failed to respond to standard replacement therapies."

MacDonald said he sees the improvements to his patients' lives first-hand, with some who were once living in the streets able to get housing, finish school, and get full-time jobs as a result of treatment.

“Whenever you have people using illicit opioids and illicit heroin, you’re going to have major health consequences and social disorder," MacDonald said. "You need every tool available to confront this epidemic and this crisis. This is one part of that response.”

Allowing doctors to prescribe heroin is part of a larger softening of Canada's approach to drugs. Prime Minister Justin Trudeau has also promised to legalize recreational use of marijuana, with a bill planned for early 2017.

Providence Health Care