Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

For nearly 30 years, Bonnie Lieberman has relied on a drug called Plaquenil to prevent a flare-up of symptoms associated with lupus: rashes, debilitating fatigue, "swollen, hot, painful joints."

"This drug is lifesaving for me because it helps me function," she said.

But when Lieberman, a preschool teacher from California, called her pharmacy Friday to check whether her new prescription was available, she got a startling reply.

"I physically don't have any medication," Lieberman, 46, said she was told. "It's back-ordered everywhere."

Full coverage of the coronavirus outbreak

Lieberman didn't have to be told why. She knew that President Donald Trump had touted the drug, known by its generic name, hydroxychloroquine, as a possible treatment for the coronavirus the day before, increasing attention on a medication that experts say was already in short supply due to surging demand.

Clinical tests are only just beginning, and infectious disease experts say it's too soon to reach a conclusion. Still, the publicity surrounding hydroxychloroquine, which began well before Trump's remarks, has fueled shortages across the country, NBC News found.

"We were starting to see some reports of supply problems earlier as hospitals started purchasing to have on hand for possible inpatient treatment / clinical trials, however Thursday’s announcement and continuing remarks are driving people to start hoarding this product," said Erin Fox, senior director of drug information at University of Utah Health, whose research on medication shortages is used by the American Society of Health-System Pharmacists.

The run on hydroxychloroquine has left people like Lieberman scrambling to get their hands on the drug.

"To affect lupus patients this way is irresponsible and dangerous," said Lieberman, a mother of two from Sunnyvale.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

"I hope they find something that helps people," she added, "but it's more that it's an unfounded thing at this point."

Hydroxychloroquine, an anti-malarial medication, has long been used by people who suffer from lupus. The autoimmune disease afflicts about 1.5 million Americans, predominantly women and African Americans.

Trump, after first highlighting the promise of hydroxychloroquine in treating the coronavirus Thursday, followed up with a series of tweets.

HYDROXYCHLOROQUINE & AZITHROMYCIN, taken together, have a real chance to be one of the biggest game changers in the history of medicine. The FDA has moved mountains - Thank You! Hopefully they will BOTH (H works better with A, International Journal of Antimicrobial Agents)..... — Donald J. Trump (@realDonaldTrump) March 21, 2020

Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, and other experts have emphasized the need for large clinical studies to determine what can be effective in fighting COVID-19. Over the weekend, Gov. Andrew Cuomo announced that New York will begin testing drugs, including hydroxychloroquine, for treatment of the coronavirus. And on Monday, Cuomo signed an amended executive order that restricts pharmacists from dispensing hydroxychloroquine and chloroquine “except when written as prescribed for an FDA-approved indication, or as part of a state approved clinical trial related to COVID-19 for a patient who has tested positive for COVID-19.”

CVS Pharmacy, which is the largest pharmacy in the U.S., said late last week that it has "adequate supply on hand" and is "taking all necessary steps to remain in stock."

But NBC News contacted a dozen late last week — in cities like Los Angeles, Chicago, Atlanta and New York — and none of them reported having the drug in stock. All said it's on back order, and they have no idea when they'll get it back in.

"I have eight patients we normally fill and can't fill them," said a CVS pharmacist in Los Angeles. "I was like, 'What's going on?' but after I watched the news, I figured it out."

Other pharmacies don't appear to be faring any better.

Calls on Monday to six Walgreens — two in Chicago and one each in Atlanta; Los Angeles; Albuquerque, New Mexico; and Belleville, New Jersey — and the same number of Rite Aids — in New York City, Los Angeles and San Francisco — produced the same responses. Not a single one said it had hydroxychloroquine in stock.

Walgreens said it's working with "manufacturers and suppliers to ensure we can meet the prescription needs of our patients" and emphasized that the Food and Drug Administration has yet to approve anti-malarial medications to treat COVID-19.

Rite-Aid did not respond to a request for comment.

In a memo to prescribers dated last Tuesday, the online pharmacy Honeybee Health expressed concern about the "increasing demand for Plaquenil during the COVID-19 outbreak."

Dr. Elizabeth Volkmann, an assistant professor of medicine in the division of rheumatology at UCLA, said her patients have struggled to get their refills beginning last Thursday when Trump first brought up hydroxychloroquine as a potential coronavirus treatment.

"With the very limited information that was given in that announcement, it caused a lot of panic among people and people started to stockpile the drug that don’t even need it," Volkmann said.

Download the NBC News app for full coverage and alerts about the coronavirus outbreak

Two major manufacturers of the drug, Teva Pharmaceuticals and Mylan Inc., say they have ramped up production, but it's not known whether it's being sent to pharmacies or hospitals dealing with COVID-19. The Lupus Foundation of America said it's working to "take steps that ensure people with lupus will be protected from a disruption in access to critical medications."

For lupus patients like Lieberman, the clock is ticking.

She said she has a two week supply left if she continues to take her normal dose. But out of fear of an extended shortage, she has already begun taking a half-dose.

"It's scary the thought of being off something that has kept me healthy for so long and functional," Lieberman said. "There's a lot of anger. There's a lot of frustration."