The man was drinking excessive amounts of energy drinks to stay awake at work.

A 50-year-old builder developed hepatitis after drinking excessive amounts of energy drinks.

The rare case has been published online in the British Medical Journal's BMJ Case Reports by doctors from the University of Florida College of Medicine.

The authors of the study have said consumers should be aware of the potential risk of energy drinks and doctors should consider the consumption of energy drinks and other herbal supplements when diagnosing hepatitis.

Hepatitis is described by the World Health Organisation (WHO) as an inflammation of the liver.

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While hepatitis viruses were the most common cause of hepatitis, it could also be caused by other infections, toxic substances such as alcohol and some drugs, and autoimmune diseases, the WHO said.

The patient in the BMJ study was found to have a hepatitis C infection, but the authors of the report said they did not think that was responsible for the acute hepatitis they treated.

The previously healthy man drank four to five energy drinks every day for three weeks to stay awake at work.

He visited the emergency department of his local hospital complaining of abdominal pain, nausea and vomiting. He originally thought he had flu until he developed jaundice - a yellowing of the skin - and dark urine.

The doctors ran tests including an ultrasound scan, blood tests and liver biopsy and diagnosed him as having chronic hepatitis C infection. Hepatitis C is a virus that If left untreated can result in cirrhosis, liver cancer or liver failure.

The man was discharged after six days.

Hepatitis is often linked to heavy alcohol or drug use, but the man's only unusual habit was his heavy consumption of energy drinks.

The doctors said the most likely cause of his hepatitis was an overdose of vitamin B3, known as niacin, which is found in high concentrations in energy drinks.

They wrote: "Each bottle of his energy drink contained 40 mg of niacin, or 200 per cent of the recommended daily value and he consumed four to five bottles daily for more than 21 days straight."

The doctors wrote: "As the energy drink market continues to rapidly expand, consumers should be aware of the potential risks of their various ingredients.

"Vitamins and nutrients, such as niacin are present in quantities that greatly exceed the recommended daily intake, lending to their high risk for harmful accumulation and toxicity."

They added: "With the increasing popularity of energy drinks, clinicians should also be aware of the potential adverse effects associated with their consumption and inquire about energy drink intake in otherwise healthy adults who present with unexplained acute hepatitis.

"By alerting physicians to this phenomenon, we hope patients will be educated about the potential risks of energy drink over-consumption, and thus, many unnecessary liver injuries will be prevented, or at least promptly identified and treated appropriately."

* This article has been updated as it previously stated the energy drinks caused the Hepatitis C infection.