TORONTO -- Two months after the COVID-19 pandemic began, pharmacists across Canada say they continue to face challenges in obtaining certain medications their patients need.

According to a new survey from the Canadian Pharmacists Association (CPhA), only three per cent of Canadian pharmacists reported receiving their full order of medications for every order placed through wholesalers during the first week of May.

The CPhA told CTVNews.ca in an email that the medications surveyed pharmacists said they were most concerned about include inhalers, Angiotensin II receptor blockers (ARBs) used to treat high blood pressure, glaucoma eye drops, narcotics such as oxycocet, and other blood pressure medications.

The survey, which was released Wednesday, reported that 56 to 60 per cent of pharmacists received reduced quantities of medication supplies on most or all orders placed during that same week, while 46 per cent of pharmacists did not receive any stock of certain medications.

Nardine Nakhla, a community pharmacist and professor at the University of Waterloo, told CTVNews.ca that the "consequences can be far-reaching" when people don’t have timely access to their medications.

"For patients without their rescue inhaler, this can mean an asthma attack. For patients without their ARB, this can mean elevated blood pressure and an increased risk of heart attack and stroke for some. For patients without their narcotic, this can mean withdrawal and a loss of tolerance, with the risk of overdose upon restarting," Nakhla said in an email on Friday.

Mina Tadrous, an assistant professor with the faculty of pharmacy at the University of Toronto, said switching to alternative medications is an option when shortages occur, but there is often still a delay in getting patients those drugs.

"If you've been on a prescription for a long time and you suddenly have to switch, it's a lot of work and extra pressure on the health-care system. You have to navigate trying to get the doctor to agree with the prescriber and then also working with the pharmacist -- it requires a lot of effort especially during a pandemic," Tadrous said Wednesday in a phone interview.

Tadrous added that pharmacists are working to find out about shortages before they happen to ensure patients have more time to consider alternatives before pharmacies run out of a certain medication.

While Canada has seen a spike in shortages during the pandemic, the CPhA says it has not yet developed into the emergency situation some health officials had feared.

However, the association said pharmacists remain "very concerned."

"While we commend Health Canada for their efforts to monitor the drug supply and mitigate the impact of COVID-19 on the health of Canadians, we urge the federal government to remain on high alert for further drug supply disruptions in the coming months due to current manufacturing disruptions in countries like China and India or future spikes in demand," it said in a news release.

Health Canada told CTVNews.ca on Wednesday it is "aware that there may be supply disruptions related to COVID-19 and [is] monitoring the situation closely."

"We will continue to use all available tools to help manage critical national shortages when they happen, and work with partners so that Canadians have access to the medications they need," Health Canada said in an email statement.

The Canadian Pharmacists Association first warned of the possibility of shortages in early March, when it noticed supply chains for ingredients and finished medications were starting to be disrupted in China. In response, the association recommended pharmacies restrict the amount of drugs they dispense to a 30-day supply per patient during the pandemic.

However, as provinces reopen their economies, the one-month limit on people's prescription drug supplies is being lifted.

CPhA spokesperson Barry Power said this is problematic because drug wholesalers continue to limit the amount of medication being shipped out, meaning pharmacies are not getting more than a 30-day supply in some cases.

"Wholesalers are still rationing what they can send to a pharmacy. So if you ordered 10 of something you might get like six and be owed the rest. With a lot of the provinces going back to 90 day dispensing, we are concerned that that's going to become a bigger issue," Power said in a phone interview on Wednesday.

Deputy Health Minister Stephen Lucas said in April that the COVID-19 pandemic will likely lead to shortages of drugs and medical devices for Canadians.

Lucas said the federal government has a team dedicated to addressing the problem and is working with regulators in the U.S., Australia and Europe to identify where the supply-chain disruptions are occurring.

The federal government has also issued an interim order to allow certain international drugs that may not fully meet regulatory requirements to be imported and sold in Canada to help address drugs shortages.

The CPhA said it continues to collaborate with governments to identify other medications most at risk of potential shortages.

"We hope that the government of Canada will continue to prioritize this issue and work with us to examine the current challenges affecting access to needed medications in Canada as well as the longer-term impacts," the release said.