Intravenous enprofylline in the treatment of patients with acute asthma

The safety and efficacy of enprofylline were studied in 55 moderately severe asthmatic patients [forced expiratory volume in 1 s (FEV1) and peak expiratory flow rate (PEFR) no more than 50% of predicted values] presenting with an acute attack. A bolus injection of 1.5 mg/kg enprofylline was given over 20 min and then maintenance infusion of 0.4 mg/kg.h enprofylline for up to 24 h. On admission, 200 mg hydrocortisone was administered intravenously and additional oxygen and/or inhaled beta 2-agonist therapy was permitted after 1 h; this additional therapy was given to 39 patients. The bolus injection increased the PEFR from 121 +/- 44 l/min to 164 +/- 49 l/min at 20 min, with a further improvement during the maintenance infusion to 200 +/- 79 l/min at 24 h. Heart rate and blood pressure decreased towards normal in parallel with the improvement in lung function. The mean steady-state enprofylline plasma concentration was slightly higher than predicted. The mean renal clearance and recovery of enprofylline from urine were in good agreement with results previously obtained from healthy Caucasian subjects.