WASHINGTON – The Food and Drug Administration is investigating 13 adverse health reports associated with people who drank Rockstar energy products, the agency said Nov. 15. The same day U.S. senators Dick Durbin of Illinois and Richard Blumenthal of Connecticut sent a letter to the F.D.A. requesting a meeting to discuss health concerns over energy drinks.

The adverse health reports associated with Rockstar took place between Jan. 1, 2004, and Oct. 23, 2012, and included such conditions as nausea, hypertension and anxiety. No deaths were reported.

The F.D.A. previously had confirmed it was investigating adverse health reports of people who had consumed Monster Energy and 5-Hour Energy products. The reports of people who had consumed 5-Hour Energy included 13 deaths. The reports of people who had consumed Monster Energy included five deaths. Rockstar, Monster Energy and 5-Hour Energy all are marketed as dietary supplements and not as beverages.

Individual adverse event reports about a particular product and the total number of adverse event reports for that product in the F.D.A.’s Adverse Event Reporting System (CAERS) only reflect information as reported, according to the F.D.A. The reports do not represent any conclusion by the F.D.A. about whether the product caused the adverse events.

The reports also have limitations, according to the F.D.A. They do not necessarily include all relevant data, such as whether a person suffered from other medical conditions or whether they took other supplements or medication at the same time. The reports also may not include accurate or complete information for the F.D.A. to seek further information about the event, and complainants may choose not to participate in a follow-up investigation.

In their letter, the two senators said they wrote it after an article in The New York Times focused on the F.D.A.’s investigation of 5-Hour Energy. Senators Durbin and Blumenthal previously wrote letters to the F.D.A. about the energy drink issue on Sept. 11 and Oct. 26.

“We have not received a response to these letters,” the Nov. 15 letter said. “Once again, we reiterate our request for the F.D.A. to investigate the interactions between caffeine consumption by children and adolescents, and to finalize and issue guidance that clearly distinguishes liquid dietary supplements from beverages.”

While healthy adults may consume 400 mg of caffeine daily, the American Academy of Pediatrics recommends adolescents consume no more than 100 mg of caffeine daily.

Rockstar products have 80 mg of caffeine per 8-oz serving. Besides caffeine, an energy blend within the product also contains taurine, ginkgo biloba leaf extract, guarana seed extract, inositol, L-carnitine, panax ginseng extract and milk thistle extract. The company does not recommend Rockstar products for children, pregnant or nursing women, or people sensitive to caffeine.

One shot of 5-Hour Energy contains about as much caffeine as a cup of a leading premium coffee, said Elaine Lutz, a spokesperson for Living Essentials, L.L.C., Farmington Hills, Mich., which distributes 5-Hour Energy shots. She said the company is unaware of any deaths that were proven to have been caused by consuming 5-Hour Energy. Women who are pregnant or nursing and children under age 12 should not drink 5-Hour Energy, according to Living Essentials.  

A 24-oz can of Monster Energy contains about 240 mg of caffeine from all sources, which is about 30% less than the average caffeine contained in a medium-sized, 16-oz cup of coffee house brewed coffee, according to Monster Beverage Corp., Corona, Calif. FBN