"Our first step would likely be with the three [diseases] for which there is no debate, and the second step to follow would be hopefully when we have got an international agreement on what other ones should be covered," a senior Ottawa official said.
Aid groups warn that setting strict limits on what diseases can be tackled with generic drug shipments from Canada would shortchange poor nations that need access to cheap treatments for a host of other health emergencies.
"If they do that, they will be kowtowing to the pressure of the brand-name pharmaceuticals, who want to limit this as much as possible for their own profits," said Mark Fried, spokesman for development group Oxfam International.
"There is no medical justification for denying medicines to people suffering from diabetes, cancer or schistosomiasis."
Development groups say Canada could be setting a restrictive international precedent. Canada is the first country setting up a system to export cheap copies of patented drugs after a World Trade Organization deal in August allowing such shipments to help treat public health problems.
Mr. Fried said the WTO deal set no limits on what diseases can be combated in this manner, and therefore what patented pharmaceuticals can be copied.
The Canadian government has not yet decided to limit diseases that will qualify for its initiative to AIDs, tuberculosis and malaria and is still consulting stakeholders, officials say.
But a senior federal official said that Ottawa does not want to get ahead of international consensus and that those three illnesses were the only ones upon which all countries agree.
"It will be far more prudent to not be so liberal in the interpretation early on" than have to wind it back, the official said, adding that Canada has asked the WTO for a more complete list of allowable diseases.
The official said addressing the three diseases first could be a "starting point" and that more maladies could be added as international consensus emerges.
"There is a long list of things that people want covered, and there is not an agreement on those."
Non-governmental organizations, concerned about the spread of disease in developing countries, urged Ottawa to change tracks and make sure the law allows exports of drugs for all medical needs.
Legislation that would restrict exports to those drugs that treat AIDS, tuberculosis and malaria, "from an ethical, medical and humanitarian point of view would make no sense," said Richard Elliott, for the Canadian HIV/AIDS Legal Network. "I think it would be terrible if they were to take that approach. . . . It would be a terrible precedent."
The Canadian brand-name drug industry has refused to comment on the matter since sending out a short news release two weeks ago saying it supported the effort to help poor countries.
If Ottawa truly intends to make the limited list a first step in a series of more significant moves, then it should include a mandated review in the legislation, Mr. Elliot said.
"First steps are always important," he said.
"We really have to question the political will to follow through with second and third and subsequent steps."
The impetus for Canada's cheap-drug export plan was the WTO deal struck in late August that allows countries to break patents and sell cheap copies of brand-name drugs to other needy nations stricken by acquired immune deficiency syndrome and other health emergencies.
It was a September plea from Stephen Lewis, the United Nations special envoy to Africa on AIDs issues, that really propelled forward this initiative by Industry Minister Allan Rock and Trade Minister Pierre Pettigrew.
