EFFECT OF ANTICHOLINERGIC DRUGS ON THE EFFICACY OF ACTIVATED CHARCOAL

Background: Although it is a commonly held tenet that drugs with anticholinergic action would prolong the duration of time for effective gastric decontamination after drug ingestion, there are no published data in support of this belief. The purpose of this study was to determine whether activated charcoal is more effective in the presence of anticholinergic activity. Methods: This was an IRB approved, human volunteer, randomized crossover study. Ten volunteers ingested 4.0 g of acetaminophen on three occasions at least one week apart. One ingestion served as a control. One hour after the other two ingestions, 50 g of activated charcoal in water was administered to each volunteer. These intervention limbs differed in that each volunteer received 0.01 mg/kg of atropine intramuscularly 15 minutes prior to acetaminophen dosing in one of them. Eight blood samples were taken over the initial 8 hours for HPLC analyses of serum for acetaminophen, which were used for calculation of pharmacokinetic parameters. Repeated measures ANOVA and Tukey's HSD test were used for statistical analyses. Results: Control pharmacokinetic parameters for acetaminophen were consistent with literature values. The mean AUC [+ or -] SD for the control, charcoal and atropine/charcoal groups were 258 [+ or -] 122, 206 [+ or -] 120, and 138 [+ or -] 88 mg/L.hr, respectively. The decreases of bioavailability were 20% for the charcoal and 47% for the atropine/charcoal groups. Charcoal was more effective when the subjects were pre-treated with atropine compared to charcoal without atropinization (p [is less than] 0.05). Conclusion: Our data support the belief that activated charcoal is more effective in the presence of anticholinergic activity.
Tenenbein M, Green R, Sitar DS. University of Manitoba, Winnipeg, Manitoba, [...]