The family of a 21-year-old Ivy League student who died after consuming Panera Bread’s Charged Lemonade – a powerfully caffeinated soda – is suing the food chain, claiming that it failed to appropriately warn customers about what they claim is a “dangerous energy drink”. According to a complaint filed on Monday in the Philadelphia court of common pleas, Sarah Katz had a heart condition and was not aware of the drink’s stimulant content. The complaint said the drink’s stimulant content exceeds that of cans of Red Bull and Monster energy drinks combined. The wrongful death lawsuit, which NBC News first obtained, says that Katz – a University of Pennsylvania student – worked as a research assistant at a children’s hospital. She had long QT syndrome type 1, a heart condition whose sufferers are advised to avoid energy drinks. A medical examiner’s report showed Katz’s cause of death was cardiac arrhythmia due to long QT syndrome. “I think everyone thinks lemonade is safe,” Elizabeth Crawford, an attorney for Katz’s family, told NBC. Crawford, a partner at the Philadelphia-based law firm Kline & Specter, added: “And really, this isn’t lemonade at all. It’s an energy drink that has lemon flavor. “It should have an adequate warning.” The student bought the Charged Lemonade drink at a Panera outlet in Philadelphia in September last year and went into cardiac arrest hours later at a birthday gathering for a friend, her family’s lawsuit claimed. “I guarantee if Sarah had known how much caffeine this was, she never would have touched it with a 10ft pole,” roommate Victoria Rose Conroy told the outlet. The lawsuit asserts that Charged Lemonade, which contains 390 milligrams of caffeine (equivalent to six expressos) was “offered side-by-side with all of Panera’s non-caffeinated and/or less caffeinated drinks”. The lawsuit says the beverage is advertised as “plant-based and clean”. The drink also contains guarana extract, a stimulant, and the equivalent of nearly 30 teaspoons of sugar, the complaint said. Katz had ordered the large cup, which is 30 fl oz, according to the attorney representing her family. “We were very saddened to learn this morning about the tragic passing of Sarah Katz, and our hearts go out to her family,” a Panera spokesperson told NBC, adding that the company believed in transparency around its ingredients and would “work quickly to thoroughly investigate this matter”. According a 2019 report by the American Heart Association, individuals with acquired or congenital long QT syndrome and those with hypertension “should be more vigilant and limit their energy drink intake”. The report estimated that the energy drink market would reach $61bn by 2021 and said that about 30% of teenagers consume them. Despite claims that they can promote performance and cognition, the report noted “detrimental side effects, particularly cardiovascular and neurological in nature”. Citing data from the US Food and Drug Administration, it said there had been 34 deaths attributed to energy drinks that warranted “investigation into the safety of these beverages”. The Philadelphia lawsuit alleges that Panera’s Charged Lemonade is “defective in design because it is a dangerous energy drink”, adding that “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”.