A Health Canada report shows a man, 18, suffered a seizure after drinking two energy drinks on an empty stomach. (Paul Chiasson/Canadian Press)

Health Canada is encouraging people to tell them about suspected adverse reactions to energy drinks and other natural health products following a report of a student who suffered a seizure.

In the latest edition of the Canadian Adverse Reaction newsletter, the agency provides the case study of an 18-year-old man who had consumed energy drinks.

The report said the man drank two 355 mL cans of Red Bull Energy Drink over a half hour on an empty stomach, for fatigue and hunger, after a night of studying. According to the report, about an hour later while in school, he experienced two grand mal seizures.

Health Canada says the student was previously well, was not taking any medication, and had no history of seizure or head injury.

He had occasionally consumed Red Bull in the past, but the night prior to the seizures he hadn't consumed any caffeinated drinks.

The report said that at the emergency department, the student's vital signs were normal and he was released from hospital the same day with only the pain medication acetaminophen as treatment. He remained seizure-free at the one-year followup mark.

Health Canada said four cases of seizure associated with energy drinks have been published.

The department said the cases describe "discrete new-onset seizures occurring in adults following heavy consumption."

In a statement emailed to The Canadian Press, Red Bull Canada said that this particular case occurred nearly a year and a half ago and had been reported to Health Canada according to regulations for natural health products.

The company's statement pointed out that two 355-mL cans of Red Bull Energy Drink contain about the same amount of caffeine as two to three cups of coffee (230 mg).

"Scientists from Health Canada have concluded that the general population of healthy adults is not at risk for potential adverse effects from caffeine if they limit their consumption to 400 mg per day," the statement said.

Red Bull Canada said the energy drink is available in 160 countries "because health authorities across the world have concluded that Red Bull Energy Drink is safe to consume."