Gomez‐Perez 1985.

Study characteristics
Methods	Single‐centre, randomised, double‐blind, placebo‐controlled, 2‐period, cross‐over design for 30 days each period
Participants	Pain model: painful diabetic neuropathy. Mean age: 55 years (30 to 73). 24 participants were randomised and 18/24 completed the 2 periods of treatment. 9/18 were women. Medications: information about concomitant analgesia is not stated.
Interventions	Nortriptyline 10 mg + fluphenazine 0.5 mg: the starting dose was 1 tablet TID for 2 weeks and it was increased 2 tablets TID for another 15 days. Identical tablets and increasing scheme were applied during the placebo period.
Outcomes	The initial level of pain and paraesthesia were given a 100% value and changes were considered positive or negative per cent deviations (mean per cent of change). VAS change from baseline was used in the outcomes assessor’s office as well as a side effects record.
Notes	Baseline pain intensity or minimum pain intensity for inclusion in the study was not reported. Small sample size. No carry‐over effect analyses.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of randomisation is not stated
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"The active drugs, 10 mg of nortriptyline and 0.5 mg of fluphenazine, and the placebo, an inactive substance, were supplied as identical tablets under a code unknown to clinicians"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement
Incomplete outcome data (attrition bias)	Unclear risk	Substantial dropout rate
Selective reporting (reporting bias)	Low risk	Not apparent selective outcome reporting. Trial was not registered.
Other bias	High risk	Fewer than 50 participants per period and < 8 weeks duration