Intal and Singulair, alone and in combination in asthma provoked by inhalation of a sugar.

The study consisted of 4 visits of approximately 1.5 hours and each visit was scheduled to take place at the same time of day. There was a minimum of 2 days between study days 1 & 2 and a minimum of 4 days with a maximum of 2 weeks between study days 2-4. The minimum time in which a study was completed was 11 days, the maximum was 26 days, with an average of 16 days taken to complete a study. Day 1: Subjects with a measured forced expiratory volume in one second (FEV1) of at least 70% predicted received a challenge with inhaled mannitol. The challenge ceased when a fall of 20% in FEV1 was achieved or 635 mg of mannitol was administered through a dry power inhaler (Osmohaler™). Subjects who recorded the 20% fall in FEV1 following the delivery of up to 315 mg were enrolled in the study. They were given a randomisation number that determined the order of administration of either placebo sodium cromoglycate (SCG) & placebo montelukast sodium (MS), SCG & placebo MS, or SCG & MS. They were given a vial containing two tablets of either montelukast sodium (10 mg) or its placebo. They were asked to take one tablet on the evening prior to their next study day, and a second tablet 3-5 hours prior to the study. On arrival at the laboratory on the subsequent study days FEV1 was measured in triplicate then SCG (2 x 20 mg) or a placebo administered by inhalation through a dry powder inhaler (Inhalator™). FEV1 was measured after 15 minutes then a challenge with mannitol followed, with the administration of the same dose that caused a 20% fall in FEV1 on the first day. Subjects recovered from challenge spontaneously, and FEV1 was measured at 5 minutes and then every 10 minutes until 30 minutes. If the FEV1 had not recovered to within 5% of baseline FEV1, 2 puffs (200 mcg) of salbutamol was administered and FEV1 monitored until it had recovered. Duration of interventions: SCG - one hour MS - 14 hours