RT Journal Article SR Electronic T1 Bronchodilation by an inhaled VPAC2 receptor agonist in patients with stable asthma JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 217 OP 221 DO 10.1136/thorax.58.3.217 VO 58 IS 3 A1 A Lindén A1 L Hansson A1 A Andersson A1 M Palmqvist A1 P Arvidsson A1 C-G Löfdahl A1 P Larsson A1 J Lötvall YR 2003 UL http://thorax.bmj.com/content/58/3/217.abstract AB Background: The synthetic vasoactive intestinal peptide (VIP) analogue Ro 25-1553 is a selective VIP-PACAP type 2 (VPAC2) receptor agonist that causes a bronchodilatory effect in guinea pigs in vivo. The effect of Ro 25-1553 given by inhalation to patients with asthma was studied and compared with that of a long acting β2 adrenoceptor agonist. Methods: Twenty four patients with moderate stable asthma participated in a double blind, randomised, placebo controlled, crossover study. The primary variable was bronchodilatory effect (increase in forced expiratory volume in 1 second, FEV1) after inhalation of Ro 25-1553 (100 μg or 600 μg) and formoterol (4.5 μg), respectively. Putative side effects were characterised by monitoring sitting blood pressure, serum potassium, electrocardiography and echocardiography. Results: Inhalation of 600 μg Ro 25-1553 caused a rapid bronchodilatory effect (geometric mean increase in FEV1 compared with placebo) within 3 minutes of 6% (95% CI 4 to 9), as did inhalation of formoterol (8% (95% CI 5 to 10)). The corresponding maximum bronchodilatory effect during 24 hours was similar for 600 μg Ro 25-1553 (7% (95% CI 4 to 10)) and the reference bronchodilator formoterol (10% (95% CI 7 to 12)). However, for both doses of Ro 25-1553 the bronchodilatory effect was attenuated 5 hours after inhalation whereas formoterol still had a bronchodilatory effect 12 hours after inhalation. Neither Ro 25-1553 nor formoterol produced any clinically relevant side effects. No drug related difference in adverse events was observed. Conclusion: Inhalation of a synthetic selective VPAC2 receptor agonist constitutes a promising approach for bronchodilation in patients with asthma.