Betel nut: a common drug used by naturalized citizens from India, Far East Asia, and the South Pacific Islands.

Betel nut is a common masticatory drug used in Far East Asia, India, and the South Pacific. It is used daily by 600 million people worldwide, yet is unknown to most Western physicians. As the world becomes more culturally and ethnically interconnected, emergency physicians will encounter the use of betel nut. Significant illness can be associated with its use, including asthma exacerbation, cholinergic crisis, cardiac arrhythmias, acute psychosis, milk-alkali syndrome, and oropharyngeal tumors. We describe its source, pharmacology, composition, presentation, and treatment in the emergency department.