Activated Charcoal in Phenobarbital Overdose

To the Editor.— Previous studies have shown that the administration of multiple oral doses of activated charcoal will decrease the elimination half-life of phenobarbital. 1,2 An uncontrolled trial in patients with phenobarbital overdose treated with this regimen suggested that coma time and duration of mechanical ventilation were decreased consistent with the decrease in phenobarbital halflife. 3 However, the obvious thesis that decreasing the half-life of phenobarbital by administering multiple doses of activated charcoal would result in a decrease in coma time and duration of mechanical ventilation in patients with phenobarbital overdose requires final proof. Pond et al 4 have tested this thesis. In a small randomized controlled trial, they have confirmed that repeated doses of activated charcoal, compared with single doses, decrease the serum half-life of phenobarbital in patients with phenobarbital overdose. But, it is surprising that the duration of mechanical ventilation was not different in the two groups. However,