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Effectiveness of delayed activated charcoal administration in simulated paracetamol (acetaminophen) overdose
Author(s) -
Yeates P. J. A.,
Thomas S. H. L.
Publication year - 2000
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1046/j.1365-2125.2000.00107.x
Subject(s) - activated charcoal , acetaminophen , crossover study , medicine , absorption (acoustics) , ingestion , antidote , oral administration , pharmacology , drug overdose , pharmacokinetics , volunteer , anesthesia , analgesic , antipyretic , chemistry , poison control , toxicity , emergency medicine , placebo , physics , alternative medicine , organic chemistry , adsorption , pathology , acoustics , agronomy , biology
Aims Oral activated charcoal is used to treat drug overdose and is effective at reducing drug absorption when administered within 1 h of drug ingestion. There are fewer data on efficacy when the delay is longer, as is the case in most drug overdoses. This study investigated the efficacy of activated charcoal at preventing paracetamol (acetaminophen) absorption after simulated overdose when administration was delayed between 1 and 4 h. Methods An open randomized‐order four‐way crossover study was performed in healthy volunteers comparing the effect of activated charcoal 50 g on the absorption of 3 g paracetamol tablets when administered after an interval of 1, 2 or 4 h or not at all. Plasma paracetamol concentrations were measured over 9 h after paracetamol ingestion using h.p.l.c. and areas under the curve between 4 and 9 h (AUC(4,9 h)) calculated as a measure of paracetamol absorption. Results Activated charcoal significantly reduced paracetamol AUC(4,9 h)when administered after 1 h (mean reduction 56%; 95% Confidence intervals 34, 78; P <0.002) or 2 h (22%; 6, 39; P <0.03) but not after 4 h (8%; −8, 24). When administered after 1 h activated charcoal reduced individual plasma paracetamol concentrations significantly at all times between 4 and 9 h after paracetamol administration. Administration at 2 or 4 h had no significant effect. Conclusions These results in healthy volunteers cannot be extrapolated directly to poisoned patients. However, they provide no evidence of efficacy for activated charcoal when administered after an interval of more than 2 h.