Behnoush 2009.

Methods	Study design: randomized controlled trial Study duration: July 2003 to September 2004 Setting: hospital setting (poisoning ward of the Loghman Hospital, Tehran) Country: Iran Number of individuals randomized: 68 Number of individuals receiving the intervention: 38 Number of individuals receiving the control: 30 Number of individuals lost to follow‐up: unclear, as loss to follow‐up was considered an exclusion criterion for the study Sample size calculated: yes, but methods are not clearly reported: "The sample size was measured according to the descriptive studies formula, and the P value was calculated based on the number of controls with carbamazepine poisoning in Loghman Hospital, in previous years."
Participants	Sex: 28 males and 40 females Age: 24.2 years, range 13‐65 years Country (if different from study authors'): NA Type, dose and timing of poisoning: Participants admitted to the poisoning ward with history of carbamazepine poisoning: Dose average (range): 6.8 g (1.2‐24 g) Delay between drug intake and admission average (range): 7.44 h (0.5 h to 15 h) Inclusion criteria: poisoning confirmed by clinical examination and paraclinical tests Exclusion criteria: taken other drugs or unknown drugs, hospitalization not needed, left hospital before completion of treatment, not possible to confirm poisoning by carbamazepine
Interventions	Intervention arm: Type: MDAC via nasogastric tube + supportive treatment (including gastric lavage) Timing: every 4 h Dose: 100 g AC per dose Frequency: several, but unknown number of doses Integrity: no information Control arm: Type: SDAC via nasogastric tube + supportive treatment (including gastric lavage) Timing: no information provided, presumably after poisoning confirmation Dose: not specified, but likely 100 g AC Frequency: 1× Integrity: no information
Outcomes	Type (unit): duration of hospitalization (h) (see Table 21) Timing: no information
Funding	No information
Notes	All 8 ICU participants, with grade III or IV level of unconsciousness received the multi‐dose treatment, thus seem not to have been randomized and were therefore not included in the analysis of hospitalization duration
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "In all patients admitted to I.C.U. and 30 patients of the ward, multiple doses of charcoal were administered, whereas the resting 30 patients ‐who were chosen randomly‐ received single doses of charcoal" Comment: not enough information to make a judgment
Allocation concealment (selection bias)	Unclear risk	Quote: "In all patients admitted to I.C.U. and 30 patients of the ward, multiple doses of charcoal were administered, whereas the resting 30 patients ‐who were chosen randomly‐ received single doses of charcoal" Comment: not enough information to make a judgment
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	Unclear risk	Quote: "The following patients were excluded from the study: those who left the hospital before the treatment process was completed" Comment: participants that did not complete the treatment process were excluded and no data is available on the number of people
Selective reporting (reporting bias)	High risk	Occurrence of complications not clearly described: unclear in which group they occurred. Drug and symptom monitoring are crucial outcomes that are lacking in this study. Especially for symptom monitoring, which was described as being the criterion for hospital discharge, this is problematic.
Other bias	Low risk	No other risk of bias detected