By Andrea Lucia

PLANO, Texas (CBSDFW.COM) – Parents of children with severe allergies are scrambling to find epinephrine injectors, potentially life-saving medication, as the start of school draws near.

Many families are trying to double up in order to keep one dose a home and another on campus.

READ MORE: Appeals Court Ruling Keeps Abortion Ban In Place In Texas

“I usually do it right before school starts, because the EpiPen has a short half-life, so that way it’ll stay for the whole school year,” said Megan Brunson, whose 11-year-old son has a severe nut allergy.

This year, though, she found nearly every pharmacy had run out.

“I started calling and calling and calling,” she said. “It didn’t matter who I called, I couldn’t find it.”

At Texas Star Pharmacy in Plano, Dr. Donna Barsky showed us the empty shelf where the injectors would be sitting, if she had any.

“Not only the EpiPen ran out, the generics run out, and the other trade name, the Auvi-Q, has run out,” she said.

READ MORE: Amtrak Train From Fort Worth Crashes In Oklahoma, Four Hurt

(NOTE: While a competing brand AUVI-Q appeared unavailable to Dr Barsky, its manufacturer, Kaleo, told CBS11 in a statement it “is able to fill, and is filling orders through our Direct Delivery service at”)

School districts are not required to provide EpiPens, but Frisco ISD, where Sam Brunson attends, said in a statement to CBS 11 that its campuses “routinely stock epinephrine in case the student does not have their own.” This year, though, the district says, even it has “had difficulty obtaining EpiPens.”

Pfizer, which helps manufactures the medication for the company Mylan, says it’s “working tirelessly to increase production and expedite shipments.”

Dr. Barsky’s computer shows she can expect more to arrive in September. Even then, there’s no guarantee.

“I’ve seen those dates come and go,” she said.

MORE NEWS: Critical Race Theory Law Could Be Behind Latest Southlake Racism Controversy

Mylan is asking customers having trouble locating EpiPens to call 1.800.796.9526.