A countrywide shortage of a common antidepressant medication has caused alarm among doctors, pharmacists and patients with mental illnesses.

Nearly a dozen pharmacies in Saskatoon and Regina have told CBC News that they have run out of bupropion— both the brand-name product Wellbutrin and its generic counterparts — and can't get more from their suppliers.

More than 12,000 patients in Saskatchewan take bupropion, according to the Ministry of Health. National figures are not readily available.

The prescription antidepressant is used to treat major depressive disorder and seasonal affective disorder.

"This might have been the drug that gave you the energy to live your life, do the things you needed to do, get on with your job, do your studies," said Dr. Sara Dungavell, a Saskatoon psychiatrist.

She said she fielded anxious phone calls from patients about the shortage.

Two pharmaceutical companies that produce generic bupropion are reporting a shortage or anticipated shortage on the Health Canada website.

The company that manufactures Wellbutrin, Bausch Health, reported its shortage to Health Canada six weeks ago. On Thursday, it told CBC News it had resolved its shortage, and Canadian pharmacies would receive the drug "imminently," depending on delivery schedules.

By Saturday afternoon, pharmacies in Calgary, Saskatoon, Regina and Winnipeg said they had yet to receive a shipment, and their pharmacists said it was still listed as unavailable in their system.

A company spokesperson wouldn't divulge why the shortage happened. Federal regulations require drug companies to report the reason for the shortage on a website, but Health Canada doesn't monitor for compliance because there are too many shortages, according to a spokesperson.

In this case, the spokesperson says Health Canada will follow up with the company.

Shortages stressful for people with mental illness

Dungavell said, until the drug is on pharmacy shelves, she will continue to worry about her psychiatric patients.

"The problem is, there might not be another drug that works as well for you, because this one is the only one that works on dopamine and norepinephrine," Dungavell said, adding that stopping the drug could "destabilize" her patients' treatment plans.

Wellbutrin extended release tablets are commonly prescribed to treat major depressive disorder. (Bausch Health)

At Lumsden Drugs, north of Regina, pharmacist Yolandi Burnett confirmed that a shortage of bupropion is more dire than a shortage of many other drugs would be. For example, a blood pressure medication might have eight equivalent drugs.

Bupropion "is in a class all on its own. So if it's not there, and it's been working for you, then it's extremely difficult for people with mental health issues," Burnett said.

Pharmacists have faxed letters to doctors warning them of the shortage and, in response, some doctors have tried to wean their patients off the drug or experimented with other drugs.

Several people who take the drug have posted in online forums about "freaking out" or "panicking" as they watch their supply dwindle. Some express concerns their depression will return. One patient said she ordered the medication online from India.

Canada 'needs to demand more transparency about what the problems are with the drug company,' says Dr. Jacalyn Duffin, a professor emerita at Queen's University. (Wieke Eefting)

Uncertainty over medication supply can be particularly difficult for people with depression and anxiety, according to Dr. Jacalyn Duffin, who teaches the history of medicine at Queen's University in Kingston, Ont.

"You cannot believe [the company's] resupply date because they constantly go in and update and extend the resupply date," Duffin said. "There's no transparency. None."

She co-authored a report for the C.D. Howe Institute in June that revealed about 1,200 drugs are in short supply in Canada every year, with at least 700 shortages at any time. The most common reasons for shortages are manufacturing disruptions or shipment delays. A shortage of generic drugs can often trigger a shortage of brand-name drugs, and vice versa.

"At times, all pharmaceutical manufacturers are faced with drug shortage situations," a spokesperson for Bausch Health said in an email to CBC News. "We understand this is challenging for patients and health-care practitioners to manage, and we're glad the situation is being resolved."

The company indicated it had begun shipments, but pharmacists in Saskatchewan said their online system still showed it as unavailable.

Duffin acknowledges that drug manufacturing is a private industry, not a charity, but argues that Health Canada should require companies to release more information about why shortages happen.

"We can't find solutions until we find the cause," Duffin said. "Canada needs to measure the drug shortage. It needs to demand more transparency about what the problems are with the drug company. … Instead of going around blaming [the drug companies], we should be trying to understand what their troubles are."