about british american tobacco British American Tobacco Acquires Reynolds

The unintended consequence: many G.I.s shifted their drug use to heroin, which was odorless and thus harder to detect

In these models, active smoking in human subjects is reproduced by exposing animals to cigarette smoke collected at the filter end of the cigarette (mainstream smoke), whereas passive smoking is mimicked by exposing animals to environmental smoke from the lit end of a smoldering cigarette (sidestream component)

Maybe its the nicotine cravings playing tricks on their minds

People who experience difficult or painful swallowing and/or unintentional weight loss should seek medical attention for an upper endoscopy or esophagogastroduodendoscopy (EGD)