Betel-nut chewing and asthma.
Two Asian patients admitted to hospital with acute severe asthma had been chewing betel nut immediately before the attacks. Arecoline, a cholinergic alkaloid, is a major constituent of Areca catechu (betel) nut and causes the euphoric effects. We sought an association between betel-nut chewing and bronchoconstriction in asthmatic patients. In vitro, arecoline caused dose-related contraction of human bronchial smooth-muscle strips, with one-tenth the potency of methacholine. In a double-blind challenge study, inhalation of arecoline caused bronchoconstriction in six of seven asthmatic patients and one of six healthy subjects; methacholine caused bronchoconstriction in all the asthmatic patients and in five controls. The geometric mean concentrations of arecoline and methacholine that caused 20% falls in the forced expiratory volume in 1 s (PC20 FEV1) in the asthmatic subjects were 5.2 mg/ml and 1.6 mg/ml, respectively. We then studied four Bengali asthmatic patients, regular users of betel nut, during a betel-nut challenge. Three showed no adverse effects, but one showed a 30% fall in FEV1 by 150 min after chewing; the effect was reproducible. In the UK, the rate of hospital admission for acute asthma is higher among Asians than among other groups in the population; betel-nut chewing may be one of several factors that affect asthma control and severity of attacks.
London Chest Hospital, UK.
R F
RF
Taylor
N
N
al-Jarad
L M
LM
John
D M
DM
Conroy
N C
NC
Barnes
D000328:Adult; D000818:Animals; D001114:Areca / Q000737:chemistry; D001115:Arecoline / Q000009:adverse effects* / Q000737:chemistry; D001249:Asthma / Q000139:chemically induced* / Q000453:epidemiology / Q000503:physiopathology; D001459:Bangladesh / Q000208:ethnology; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006168:Guinea Pigs; D006782:Hospitals, Special; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D016210:Methacholine Chloride / Q000009:adverse effects / Q000737:chemistry; D008875:Middle Aged; D010946:Plants, Medicinal; D012307:Risk Factors
D016210:Methacholine Chloride; D001115:Arecoline