The utility of a long-acting sympathomimetic agent, procaterol, for nocturnal asthma

Patients with nocturnal asthma have their lowest pulmonary function and lowest serum epinephrine level at 4 to 6 AM. We studied a new long-acting beta-adrenergic agonist, procaterol, in ten patients with nocturnal asthma. The patients received 0.1 mg of procaterol one night and a placebo the other night in random order. Pulmonary function tests were performed every two hours from 10 PM to 8 AM. Pulmonary sounds were recorded using a modified stethoscope and were subsequently analyzed to estimate the proportion of time occupied by wheezing (est Tw/Ttot). The forced expiratory volume in one second (FEV1) while receiving the placebo and procaterol were similar at 10 PM (placebo, 1.35 +/- 0.18 L [mean +/- SE]; procaterol, 1.48 +/- 0.20 L); however, by 4 AM, the FEV1 had dropped significantly lower on the night with the placebo (1.01 +/- 0.14 L) than the night with procaterol (1.30 +/- 0.19 L; p less than 0.05). The est Tw/Ttot was similar at 12 AM for both nights, but at 4 AM, there was a significant increase in the est Tw/Ttot for the group with placebo but not the group with procaterol. The use of a long-acting beta-adrenergic sympathomimetic agent reversed the obstruction of the airways seen with nocturnal asthma.