HALIFAX -- Pharmacist Shannon Jardine spends more and more time these days helping patients whose prescriptions can't be filled because of drug shortages, and when those shortages happen, there's little to no notice.

"Sometimes, if there's a rumbling that there's going to go short, we're able to order in just a little bit of excess, but that doesn't necessarily last us the duration of the shortage," Jardine said.

That leaves Jardine trying to find substitutions and working with doctors on medical alternatives.

"And sometimes, it's a matter of kind of just rejigging the supply and only giving patients a short-term supply until we're able to get things back," Jardine said.

There are close to 2,000 drug shortages in Canada right now, according to Health Canada's mandatory reporting website.

They include a chemotherapy drug, blood pressure medications, and pain killers.

Reasons given vary from manufacturing disruptions to shipping delays.

The lengths of shortages can be anywhere from days to months.

When it comes to the current national shortage of the breast cancer drug Tamoxifen, Health Canada says the three manufacturers are reporting the shortages because of manufacturing disruptions and increased demand.

In a statement, it says Health Canada is working with the companies, provinces and territories, stakeholders and health-care professionals, to share information and identify mitigation measures, including exploring access to international supply.

"It's a significant concern and trending in the wrong direction, for sure," said Paul Blanchard, the executive director of the New Brunswick Pharmacists' Association.

He says the federal government needs to do more to determine exact causes and act on them.

"And it's important because we're talking about a national pharmacare program and if, for example, price sensitivity is driving drug shortages, then we need to be aware of that," Blanchard said.

While breast cancer patient Wendy Ackerley has managed to obtain her supply of Tamoxifen through pharmacies in several different communities, she says the fight isn't over.

"Talk to your MLAs, talk to your MPs, talk to the health minister, and really try to get answers and push for change in this, because in Canada, this is not acceptable," Ackerley said.

As concern grows for the one in four Canadians who have been affected by medications in short supply, the national group representing Canadian pharmacists says the Trump administration's plan to import Canadian medications south of the border may add to what the association calls a "growing crisis" when it comes to our drug supply.