[Clinical study on benefit and safety of frequent inhalation of aerosolized procaterol hydrochloride in aged acute asthmatics].

We studied the hemodynamic effects of frequent inhalation of aerosolized procaterol hydrochloride (PRC) in the treatment of status asthmaticus. Twenty patients were enrolled and divided into 2 groups; younger group (less than 55 years; n = 11) and older group (more than 55 years; n = 9). All patients were treated with intravenous hydrocortisone (4 mg/kg/4 h) and PRC inhalation (30 micrograms; 0.3 ml) every hour via a jet nebulizer with 3 l/min oxygen for four consecutive days. Holter ECG monitoring was performed on the 1st, 4th, and 7th days of hospitalization to evaluate mean heart rate, tachycardiac incidence, and arrhythmias. Blood pressure, serum potassium levels, and peak expiratory flow rate (PEFR) were measured on the same day. Even though the total dosage of inhaled PRC on the 1st day was 496.4 +/- 62.61 micrograms for the younger group and 490.0 +/- 36.73 micrograms for the older group (p = NS), total arrhythmic ratios were less than 1% in both group. Both blood pressure and heart rate decreased with improvement of symptoms and PEFR value. Serum potassium levels tended to decline according to the administered dosage of PRC (p < 0.01); however, severe hypokalemia less than 3.0 mmol/l was not observed. We conclude that frequent inhalation of PRC (up to 500 micrograms/day) via a jet nebulizer provides rapid relief from acute asthmatic attacks, and is safe clinically even in aged asthmatics receiving intravenous steroids.