Vilalta 1987.

Methods	Randomised, controlled, double‐blind trial
Participants	Setting: inpatient, hospital, Barcelona, Spain. Participants: 32 heroin users, admitted for treatment of organic disease (mainly infectious disease related to consumption of drugs). Group sizes: (1) n = 14, (2) n = 8, (3) n = 10. Mean age: 23 years. 65% men.
Interventions	(1) Methadone, 30 mg/day. (2) Clonidine, 10 μg/kg/day. (3) Levomepromazine (neuroleptic) 75 mg/day. Doses of all drugs increased until stable, maintained 3 days, then tapered. Treatment scheduled for around 8 days
Outcomes	Mean opioid withdrawal score; mean score of secondary effects; mean score of adjustment to hospital setting; number completing treatment
Notes	Ratings of withdrawal (24 items), side effects (19 items), attitudes and disruptive behaviour during hospitalisation (11 items) daily by single observer. Urine screening used. Source of funding not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Allocation by random numbers table
Allocation concealment (selection bias)	Unclear risk	Method not reported
Blinding (performance bias and detection bias) Subjective outcomes ‐ intensity of withdrawal, adverse effects	Low risk	Double‐blind stated
Blinding (performance bias and detection bias) Objective outcomes ‐ duration of treatment, completion of treatment	Low risk	Double‐blind stated
Incomplete outcome data (attrition bias) All outcomes	Low risk	Difference in drop‐out rates insufficient to distort reported outcomes
Selective reporting (reporting bias)	Low risk	None apparent
Other bias	Low risk	None apparent