Pond 1995.

Methods	Study design: randomized controlled trial Study duration: recruitment period from 4 January 1988 to 11 June 1990 (29 months) Setting: hospital setting: emergency department of a tertiary referral hospital (Princess Alexandra Hospital, Brisbane) Country: Australia Number of individuals randomized: 876 Number of individuals receiving the intervention: 459 (ipecac or lavage) Ipecac: 220 Gastric lavage: 209 Number of individuals receiving the control: 417 (charcoal, oral or nasogastrically) AC: 274 Nasogastric tube: 133 Number of individuals lost to follow‐up: 82 Sample size calculated: post hoc power calculation
Participants	Sex: 377 males and 499 females Age: male: 30 (SD 11; range 14‐82 years); female: 30 (SD 1; range 13‐81 years) Intervention: 30 (SD 12 years (range 13‐76 years) Control: 31 (SD 13 years; range 13‐82 years) Country (if different from study authors'): NA Type, dose and timing of poisoning: Participants presenting within 12 h of drug overdose (adsorbing to AC) whether accidental, intended or during recreational use, at the emergency department. Most presented earlier (140 < 1 h). 59% ingested more than 1 drug Ingestion of paracetamol, salicylate, phenothiazines or ethanol, or other drugs Inclusion criteria: history of drug overdose, whether accidental, intended or recreational, > 13 years old Exclusion criteria: ingestion > 12 h before presentation, treated in a way breaching the protocol, gastric emptying contraindicated, gastric emptying indicated for diagnostic purposes, substance not adsorbed by AC. Confirmation of intoxication by measuring in serum/blood
Interventions	Intervention arm: Type: gastric emptying, being via ipecac in conscious and gastric lavage in obtunted participants. All participants received activated charcoal (Norit "C" Extra) in a slurry with 200 mL sorbitol. AC was given after ipecac‐induced vomiting had ceased or after gastric lavage Timing: before receiving AC‐sorbitol Dose: 30‐50 mL ipecac followed by 200 mL water; at least 2 L tap water for gastric lavage, via nasogastric tube Frequency: 1×, repeated if no vomiting within 30 min Integrity: no information Control arm: Type: activated charcoal‐sorbitol + supportive and drug‐specific treatment, orally in conscious and via nasogastric tube in obtunted participants Timing: after diagnosis and allocation to treatment group Dose: 50 g AC in 200 mL 70% sorbitol slurry Frequency: 1× Integrity: no information
Outcomes	Type (unit): Proportion with clinical deterioration in the first 6 h after treatment Number of days hospitalized (for medical indication related to overdose or its treatment and complications) Number of complications Admission to ward/ICU Timing: clinical course was assessed over the first 6 h at 1‐2 h intervals (early)
Funding	No information
Notes	Data for gastric lavage was not extracted, because not within scope of this review
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "Patients were allocated to one of two groups: those who presented on odd‐numbered dates to the emptied (E) group; those on even‐numbered days to the not‐emptied (NE) group." Comment: no adequate randomization
Allocation concealment (selection bias)	High risk	Quote: "Patients were allocated to one of two groups: those who presented on odd‐numbered dates to the emptied (E) group; those on even‐numbered days to the not‐emptied (NE) group." Comment: allocation was not concealed, as randomisation scheme is predictable
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were not blinded (not possible due to difference in interventions); might influence outcomes.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information on blinding, but might affect assessment of subjective outcomes (clinical deterioration)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Not all participants allocated were treated, but the number remains small (9%) and reasons are thoroughly justified
Selective reporting (reporting bias)	High risk	Certain outcomes (no. referred to wards/ICU, type of complication) only reported for gastric emptying group as a whole, not stratified per treatment
Other bias	Low risk	No other risk of bias detected