Table 3

Author, date, and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study weaknesses
PRCT = prospective randomised controlled trial.
Crone et al, 1977, UK¹	Health volunteers given 75 mg nortriptyline	Experimental	Plasma nortriptyline level	60% decreased	Small dose of TCA
	10 g medicoal at 30 min
Crome et al, 1983, UK²	48 patients with suspected TCA overdose. All had gastric lavage	PRCT	Plasma TCA concentration	No difference in rate of fall noted	Small numbers with complications. Small charcoal dose. 18 patents excluded
	10 g medicoal v nothing		Clinical signs	No significant difference
Karkkainen and Neuvonin, 1986, Germany³	6 healthy volunteers. Each took 75 mg amitriptyline	Experimental	Plasma TCA absorption	Decreased by 99%	Small dose of TCA Unrealistic time to charcoal
	50 g charcoal within 5 min
Hulten et al, 1988, Multinational⁴	77 patients over 14 years old with TCA overdose. All had gastric lavage	PRCT	Plasma TCA concentration	No significant difference in peak or half life	Control group differed from charcoal group at baseline
	20 g charcoal v nothing		Clinical signs	No significant difference