A number of leading figures in Canadian public health are criticizing the federal government's approach to drug policy, suggesting political ideology is trumping scientific evidence.

In a two-pronged attack, the chief medical officers of health for British Columbia, Saskatchewan and Nova Scotia are publishing a commentary in the journal Open Medicine today that calls on the government to rethink strategies like minimum mandatory sentences for minor drug-related offences.

Cannabis prohibition in particular is argued to have not only failed to limit the availability of the drug -- which is argued to be relatively safe compared to existing legal substances like cigarettes and alcohol -- but has let organized crime flourish as well.  

And the Urban Public Health Network, a group that represents the chief public health officers in Canada's 18 largest municipalities, has announced its endorsement of the Vienna Declaration, which calls on governments to draft drug policies based on evidence of what works.

"Basically what we're saying is that we don't think that the model we're using is particularly effective," said Dr. Perry Kendall, British Columbia's chief medical officer of health.

"In fact, there's some evidence that it's very ineffective and creates a whole class of harms which wouldn't be there if we're weren't dealing with drugs in this particular way."

Kendall, Dr. Robert Strang of Nova Scotia and Dr. Moira McKinnon on Saskatchewan co-authored an analysis that shows that a war-on-drug type approach to illegal drug use has both failed to control drugs and given rise to a series of social ills, such as drug violence and the spread of infectious disease like hepatitis C and HIV.

They said the views they expressed were their own, and they were not speaking for their individual provinces.

"If our objective is to minimize drug use, minimize health and social impacts from drug use, we need to be open to having policy and public discussions that look at all aspects and all potential ways to approach this, not just our current ideologically single approach," Strang said.

The three wrote the article with Dr. Evan Wood, of the B.C. Centre for Excellence in HIV/AIDS. The centre was one of the instigators behind the Vienna Declaration, which was launched at the International AIDS Conference in the Austrian capital in 2010.

Canadian society, they wrote, would benefit if drug policies dealt with drug addiction as a health problem rather than as a criminal justice issue. And they noted that Canada is moving to mandatory minimum sentences at a time when a number of U.S. states are repealing their legislation because it has proved to be a failure.

Mandatory minimum sentences are a provision of the omnibus federal crime bill that was given Royal Assent two weeks ago.

Several of the public health leaders speaking out suggested that when it comes to drug policy, ideology has more pull than science these days at the federal level.

"Medicine, including public health, is intended to be -- at least in the modern era -- an evidence-based business, in which you do the things that you know or have reason to believe are going to work. The same should be true of drug policy," said Dr. David McKeown, medical officer of health for Toronto.

"If we took an ideological approach in other areas of health -- started treating people's heart disease based on how we feel about their morals -- I don't think people would feel that that was an appropriate approach."

In the Open Medicine analysis, the provincial chief medical officers noted that despite the fact that law enforcement-centred drug policy has focused on trying to reduce the availability of cannabis, the drug remains widely available. And criminalizing the trade in the drug has driven the market into the hands of criminal gangs.

They noted that while critics of drug policy reform argue that policies based on health issues -- things like harm reduction programs like needle exchanges -- will increase drug use, there is no evidence to support the contention. Instead, they pointed to Portugal, which decriminalized all drug use a decade ago and has seen no increases in drug-related harms.

Does that mean they are suggesting Canada should follow Portugal's lead? Strang said he thinks different classes of drugs will need to be looked at separately, but a discussion is worth having.

"We need to be open to at least saying: What would that do? Maybe it would make things better, maybe it would make things worse, but at least let's be open to having the discussion (and) looking at evidence in other jurisdictions which may have done this," he said.