Heymann 2001.

Study characteristics
Methods	Design: parallel Duration: 8 weeks Assessment: baseline and post‐intervention Country: Brazil
Participants	Pain condition: fibromyalgia Population: women with fibromyalgia Minimum pain intensity: no Inclusion criteria Women with fibromyalgia meeting the ACR criteria Exclusion criteria Physical health comorbidities Use of nortriptyline or amitriptyline at any point Total participants randomised: 118 Age in years (mean): 50.5 Gender: 118/118 were female Pain duration in years (mean, SD): NR
Interventions	Placebo n = 40 Inert Identical tablets, matched dosing Amitriptyline 25 mg n = 40 TCA Fixed dose Nortriptyline 25 mg n = 38 TCA Fixed dose
Outcomes	Quality of life SAEs Withdrawal
Missing data methods	Completer analysis
Funding source	NR
Conflicts of interest	NR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised using random number tables
Allocation concealment (selection bias)	Unclear risk	Allocation procedures NR
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, all study drugs were identical in appearance and packaging
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐reported outcomes from blinded participants
Incomplete outcome data (attrition bias) All outcomes	High risk	Much higher attrition in the placebo group than intervention groups. No missing data methods; report only completer analysis Attrition Total: 12/118 (10.2%) Amitriptyline 25 mg: 3/40 (7.5%) Nortriptyline 25 mg: 2/38 (5.3%) Placebo: 7/40 (17.5%)
Selective reporting (reporting bias)	Unclear risk	No protocol or trial registration found
Other bias	Low risk	No other sources of bias were identified