Enhancement of theophylline clearance by oral activated charcoal

Abstract

A randomized crossover trial of the effect of oral activated charcoal on the kinetics of i.v. theophylline was carried out in 6 normal male subjects. After i.v. aminophylline (6 mg/kg), subjects received water or water with activated charcoal (140 g) in divided doses over 12 h. Serum theophylline concentrations were measured from 0-24 h after the aminophylline infusion. Treatment with activated charcoal decreased the serum t1/2 [half-life] from 6.4 .+-. 1.2 to 3.3 .+-. 0.4 h and the serum AUC [area under the plasma concentration time curve] from 78 .+-. 14 to 42 .+-. 4 mg .cntdot. h/l. Percent decrease in AUC after treatment with charcoal correlated positively with the endogenous theophylline serum t1/2 (r = 0.94). Apparently, oral activated charcoal enhanced the total body clearance of theophylline and may be efficacious in the treatment of theophylline poisoning, especially in patients with prolonged serum t1/2 of theophylline.