The effect of polymorphisms of the β2-adrenergic receptor on the response to regular use of albuterol in asthma

Inhaled β -adrenergic agonists are the most commonly used medications for the treatment of asthma although there is evidence that regular use may produce adverse effects in some patients. Polymorphisms of the β2-adrenergic receptor ( β2-AR) can affect regulation of the receptor. Smaller studies examining the effects of such polymorphisms on the response to β -agonist therapy have produced inconsistent results. We examined whether polymorphisms at codon 16 ( β2-AR-16) and codon 27 ( β2-AR-27) of the β2-AR might affect the response to regular versus as-needed use of albuterol by genotyping the 190 asthmatics who had participated in a trial examining the effects of regular versus as needed albuterol use. During the 16-wk treatment period there was a small decline in morning peak expiratory flow in patients homozygous for arginine at B2-AR-16 (Arg/Arg) who used albuterol regularly. This effect was magnified during a 4-wk run out period, during which all patients returned to using as-needed albuterol, so that ...