Picumeterol (GR114297A) is a potent and highly selective beta2-adrenoceptor agonist with a longer duration of action than salbutamol, but shorter than salmeterol. Picumeterol is the (R)-isomer of the racemic entity GR63411B, and picumeterol has been shown to be about 40 times more potent than the (S)-isomer (GR114744A) in various in vitro pharmacological models of beta2-agonist activity. Picumeterol is of potential value in the treatment of asthma and related diseases in man following inhalation administration. In the clinical studies, the bronchodilator potencies of picumeterol and GR 63411B were similar. However, both drugs were short-acting, which is at odds with their activity in vitro. These compounds display dissociation between bronchodilator activity and protection against methacholine-induced bronchoconstriction.