TAMPA, Fla. (WFLA) – The family of a 21-year-old college student is suing Panera Bread after their daughter, Sarah Katz, died after drinking the restaurant’s Charged Lemonade.

The complaint, which was filed in the Philadelphia Court of Common Pleas on Monday, called the beverage a “dangerous drink,” as a large cup of the lemonade contains more caffeine than cans of Red Bull and Monster energy drinks combined.

Katz, who was a prominent student at the University of Pennsylvania, was diagnosed with a heart condition called long QT syndrome type 1 when she was 5.

The American Heart Association describes long QT as a disorder of the heart’s electrical system that can cause abnormal heart rhythms as a result of exercise or stress; it can be well-managed with medication.

Due to her condition, doctors recommended avoiding energy drinks – and she did.

“In addition to taking daily medication and following all medical advice, [Katz] effectively managed her condition by abstaining from energy drinks and highly caffeinated beverages,” the lawsuit reads.

According to the suit, about a week and a half before her death, Katz bought an Unlimited Sip Club membership from Panera, which allows customers to pay a monthly fee for unlimited drinks.

On Sept. 10, 2022, the day of her death, Katz had a large Charged Lemonade, the lawsuit says. A few hours later, while at a restaurant for her friend’s birthday, she collapsed. The 21-year-old was taken to the hospital, where she fell into cardiac arrest again. However, the second time was fatal, according to the lawsuit.

According to NBC News, the medical examiner’s report revealed Katz’s cause of death was cardiac arrhythmia due to her underlying heart condition. The report said the beverage was a contributing factor but noted the college student did not have drugs in her system other than what the hospital used to try to resuscitate her.

On Monday, a Panera spokesperson released a statement to NBC News saying: “We were very saddened to learn this morning about the tragic passing of Sarah Katz, and our hearts go out to her family. At Panera, we strongly believe in transparency around our ingredients. We will work quickly to thoroughly investigate this matter.”

According to photos of the menu and drink station included in the lawsuit, Panera’s Charged Lemonade was “offered side-by-side with all of Panera’s non-caffeinated and/or less caffeinated drinks.” Furthermore, the suit said the lemonade was not advertised as an “energy drink.”

The beverage was also advertised as “plant-based and clean” and that it contained as much caffeine as Panera’s dark roast coffee.

However, according to Panera’s website, the 390 milligrams of caffeine in the large Charged Lemonade contains more caffeine than any size of the restaurant’s dark roast coffee. The drink also has guarana extract, another stimulant, as well as the equivalent of nearly 30 teaspoons of sugar.

Panera Bread’s website states that the caffeine content of its Charged Lemonade ranges from 260 milligrams in the regular size to 390 milligrams in the large, 30-ounce size, while the caffeine content of its dark roast coffee ranges from 161 milligrams in a small cup to 268 milligrams in a large cup, which is 20 fluid ounces.

The lawsuit alleges the Charged Lemonade is “defective in design because it is a dangerous energy drink.”

“These unregulated beverages include no warning of any potentially dangerous effects, even the life-threatening effects on blood pressure, heart rate, and/or brain function,” it read.

While Panera’s website does refer to its Charged Lemonades as “the ultimate energy drink,” the lawsuit alleges that it was not advertised as such at the time of Katz’s death.

According to the Food and Drug Administration, the caffeine limit for healthy adults is about 400 milligrams a day or about four or five cups of coffee, as that amount is “not generally associated with dangerous and negative effects.” Panera’s 390 milligrams puts the drink just below the healthy limit.