RIVERSIDE, CALIF. — The safety of energy drinks became news again on Oct. 17 when a wrongful death lawsuit was filed against Monster Beverage Corp.

Plaintiffs Wendy Crossland and Richard Fournier, parents of the late Anais Fournier and residents of Maryland, filed the lawsuit in the Superior Court of the state of California in Riverside. Anais Fournier, then 14, died on Dec. 23, 2011.

According to the lawsuit, Anais Fournier consumed a 24-oz Monster Energy drink on Dec. 16, 2011. The next day she consumed another 24-oz Monster Energy drink. The two cans together contained 480 mg of caffeine. Monster Energy drinks also contain guarana, which is a plant extract that contains caffeine, and taurine, which has an effect on cardiac muscles similar to that of caffeine, according to the lawsuit.

A few hours after drinking the second beverage, Anais Fournier went into cardiac arrest. Doctors at Johns Hopkins Hospital placed her in an induced coma in an effort to reduce brain swelling. She remained in the coma for nearly six days until a decision was made to terminate life support.

The cause of death was listed as “cardiac arrhythmia due to caffeine toxicity complicating mitral valve regurgitation in the setting of Ehlers-Danlos syndrome.” According to the Mayo Clinic, Ehlers-Danlos syndrome is a group of inherited disorders that affect connective tissues, primarily skin, joints and blood vessel walls.

According to the lawsuit, Monster Energy drinks are categorized as dietary supplements, and not foods or beverages. Monster Beverage Corp., Corona, Calif., thus manufactures the product without any restriction on caffeine content. The F.D.A. earlier this year said it plans to provide final guidance to industry on how to categorize and label energy drinks.

The lawsuit also stated Monster Energy drinks lack adequate labeling and consumers thus are unaware of how much caffeine they are ingesting. According to the lawsuit, Monster Energy drinks are marketed toward teenagers and young adults who are susceptible to caffeine-related injury.

“Defendant’s failure in designing, manufacturing, marketing, distributing, warning and/or selling Monster Energy drinks directly and proximately caused Anais Fournier to suffer the cardiac arrhythmia that ultimately led to her death,” the lawsuit said.

A Bloomberg news report included an e-mailed statement from Monster Beverage that responded to the lawsuit.

“Over the past 16 years Monster has sold more than 8 billion energy drinks, which have been safely consumed worldwide,” Monster Beverage said. “Monster does not believe that its beverages are in any way responsible for the death of Ms. Fournier. Monster is unaware of any fatality anywhere that has been caused by its drinks.”

Shares of Monster Beverage on the NASDAQ Global Select Market fell on Oct. 22 to a close of $45.73 per share after an opening of $53.46 per share.

Food Business Newscontacted the Food and Drug Administration about reports that the agency is investigating a possible connection between energy drinks and the deaths of five people.

“As with any reports of a death or injury the agency receives we take them very seriously and investigate diligently,” said Shelly Burgess, an F.D.A. spokesperson. “Under the law, adverse event reports serve as a signal to F.D.A. and do not prove causation between a product or ingredient and an adverse event.”

Because of the law, the F.D.A. has restrictions that prevent it from discussing specific information, she said.

The law requires manufacturers to submit all reports on serious adverse events to the F.D.A. within 15 days of receiving them, Ms. Burgess said.

“F.D.A. continues to evaluate the emerging science on a variety of ingredients, including caffeine,” she said.

Energy drinks were the subject of a letter that two U.S. senators, Dick Durbin of Illinois and Richard Blumenthal of Connecticut, sent Sept. 11 to the F.D.A. It focused on the interaction of ingredients, including taurine and guarana, in energy drinks and the effect the caffeine in the drinks has on children. While healthy adults may consume 400 mg of caffeine daily, the letter cited a recommendation from the American Academy of Pediatrics that adolescents consume no more than 100 mg of caffeine daily.