| Abstract: |
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.
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