Carbamazepine overdose--the effects of multiple dose activated charcoal.

We studied five children with carbamazepine overdose. Two patients had acute overdose without previous exposure to carbamazepine while three presented with acute-on-chronic overdose. Multiple doses of activated charcoal were administered to four patients. One acute-on-chronic patient did not receive any activated charcoal. The mean half-life of carbamazepine was as follows: a) Acute vs. Acute-On-Chronic overdose: 8.63 h vs. 12.01 h (p less than 0.05); b) No Activated Charcoal vs. 30-50 g Activated Charcoal vs. 60-90 g Activated Charcoal: 23.3 h vs. 10.17 h vs. 7.21 h (p less than 0.05); c) No Activated Charcoal vs. 2-3 doses vs. 7-12 doses: 23.3 h vs. 8.96 h vs 7.55 h (ns). Although the half-life of carbamazepine decreased in a linear relationship with the total amount of activated charcoal administered (r = -0.86), there was no relationship between the time to complete recovery and administration of multiple doses of activated charcoal. Although multiple doses of activated charcoal increased the clearance of carbamazepine in our patients with overdose, it was not associated with clinical benefits.