Disposition of theophylline after a single intravenous infusion of aminophylline.

Abstract

Theophylline serum concentration and disposition after a single 30-min intravenous infusion of 7.4 ± 1 mg of anhydrous theophylline per kg of body weight were determined in 20 otherwise healthy adult asthmatic volunteers using high-pressure cation-exchange chromatography. This dose resulted in a mean peak serum concentration of 18 ± 3.3 μg per ml, which remained > 10 μg per ml for 6 hours and > 5 μg per ml for the entire 12-hour period of observation. The rate of theophylline elimination in these subjects was generally slower than previously reported. Among the 4 cigarette smokers, however, theophylline plasma clearance was significantly (P < 0.001) more rapid than that observed in the 16 nonsmokers. Theophylline clearance was highly correlated with elimination half-life (r = 0.83, P < 0.001). These data support previous recommendations for an intravenous loading dose of 5 mg of theophylline per kg of body weight (6 mg of aminophylline per kg) when a mean increase in serum concentration of approximately 1...