Hultén 1988.

Methods	Study design: randomized controlled trial Study duration: no information Setting: hospital setting Country: Sweden Number of individuals randomized: 91 Number of individuals receiving the intervention: 34 Number of individuals receiving the control: 43 Number of individuals lost to follow‐up: 14 Sample size calculated: no information
Participants	Sex: no information Age: older than 14 years Country (if different from study authors'): UK, Belgium, Sweden Type, dose and timing of poisoning: 32 participants took amitriptyline, 16 clomipramine, 10 mianserin, 9 imipramine, 6 dothiepin, 2 doxepin, 2 nortriptyline, mixed overdoses in 67% with most commonly benzodiazepines or alcohol Inclusion criteria: participants with self‐poisoning with 1 or more of 7 different TCA (mixed overdoses also included if clinician considered 1 of 7 TCA drugs was major cause of participants' symptoms) Exclusion criteria: participants < 14 years old, taken significant amount of other drugs Plasma TCA concentration < 0.3 µg/L
Interventions	Intervention arm: Type: activated charcoal (MedicoalR) after gastric lavage Timing: no information Dose: 20 g Frequency: 1× Integrity: no information Control arm: Type: gastric lavage Timing: no information Dose: no information Frequency: 1× Integrity: no information
Outcomes	Type (unit): AUC ((mg/L) × h) Blood pressure (mmHg) Heart rate (bpm) Coma grade (Matthew‐Lawson coma scale) Symptoms: e.g. convulsions, arrhythmias, muscle twitching Number of participants intubated Time spent intubated Time admitted to ICU (see Table 21) Time admitted to hospital (see Table 21) Timing: Plasma drug concentration at 0 h, 1 h, 2 h, 4 h, 8 h and 24 h (intermediate) Blood pressure, heart rate, coma grade and symptoms at 0 h, 4 h, 8 h and 24 h (intermediate)
Funding	No information
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was performed by using rand numbers and equilibration made by groups of 10." Comment: adequate randomization
Allocation concealment (selection bias)	Unclear risk	Quote: "Randomization was performed by using rand numbers and equilibration made by groups of 10." Comment: not enough information to make a judgement
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No information to support judgment, but lack of blinding may affect outcomes studied
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information to support judgment, but lack of blinding may affect outcomes studied
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "14 patients were excluded because they had taken a significant amount of other drugs" Comment: adequate explanation
Selective reporting (reporting bias)	Low risk	All pre‐specified outcomes have been reported
Other bias	Low risk	No other risk of bias detected