At least two people have become intoxicated by drinking hand-sanitizing gels, a potentially deadly habit, doctors reported on Wednesday.

A prison inmate and a hospitalized alcoholic both were treated for poisoning from the gels, which contain alcohol - but not the same kind as found in beverages.

Evidently people misunderstand the labels that show the gels, foams and liquids contain alcohol, the doctors said in separate letters to The New England Journal of Medicine. Cases of people drinking the hand gels because of their alcohol content have not previously been reported in major medical journals.

“The Maryland Poison Center was called about a 49-year-old, usually calm prison inmate who was described as being ‘red-eyed,’ ‘loony,’ ‘combative,’ and ‘intoxicated, lecturing everyone about life’,” Dr. Suzanne Doyon of the Maryland Poison Center and Dr. Christopher Welsh of the University of Maryland School of Medicine wrote in one letter.

“Other inmates and staff reported seeing this prisoner drinking from a gallon container of Purell hand sanitizer over the course of the evening. “

In the second case, a 43-year-old man with alcoholism was treated for mysterious chest pains and other symptoms.

“Before those results were obtained, the patient was seen in the bathroom drinking the alcohol-based hand wash from its dispenser,” Dr. Ashkan Emadi and Dr. LeAnn Coberly of the University of Cincinnati wrote.

“When asked why he ingested the hand cleaner, he pointed to the label, which read, ‘Active ingredient 63 percent v/v isopropyl alcohol.’ He explained that this percentage is higher than that in vodka,” they added.

It only takes a small amount of isopropanol to kill, by depressing the heart and central nervous system, they wrote.

They suggest that makers of the hand gels change the labeling.