Watson 1998.

Study characteristics
Methods	Design: cross‐over Duration: each cross‐over period lasted 5 weeks Assessment: baseline and post‐cross‐over period Country: Canada
Participants	Pain condition: post‐herpetic neuralgia Population: adults with post‐herpetic neuralgia Minimum pain intensity: pain of at least moderate severity (disagreeable, unpleasant, uncomfortable) for at least one half of the day; no numerical values Inclusion criteria Post‐herpetic neuralgia of > 3 months' duration Pain of at least moderate severity (disagreeable, unpleasant, uncomfortable) for at least one half of the day Exclusion criteria Cardiac disease, seizure disorder, severe depression with voiced suicidal intent requiring urgent management, presence of another significant pain problem, previous brain damage due to head injury, stroke or other causes, alcoholism Total participants randomised: 33 Age in years (mean, SD): NR Gender: NR Pain duration in months (median): 13 months
Interventions	Nortriptyline TCA Flexible dose: 10‐160 mg Flexible titration: started on 10 mg/day if > 65 years old or 20 mg/day if < 65 years old. Depending on efficacy and tolerability, the dose was increased by 10 mg/day every 3‐5 days for the first 3 weeks. Identical blue capsules Amitriptyline TCA Flexible dose: 10‐160 mg Flexible titration: started on 10 mg/day if > 65 years old or 20 mg/day if < 65 years old. Depending on efficacy and tolerability, the dose was increased by 10 mg/day every 3‐5 days for the first 3 weeks. Identical blue capsules
Outcomes	AEs Withdrawal
Missing data methods	Unclear
Funding source	NR
Conflicts of interest	NR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Individuals were randomised by telephone at another site by computer.
Allocation concealment (selection bias)	Low risk	The sequence was concealed in sequential, numbered, sealed envelopes.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, identical study drugs
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐reported outcomes by blinded participants
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data methods unclear, but only 1 participant withdrew Attrition Total: 2/33 (6.1%) Amitriptyline 10‐160 mg: 1/33 (3.0%) Nortriptyline 10‐150 mg: 1/33 (3.0%)
Selective reporting (reporting bias)	Unclear risk	No protocol or trial registration found
Other bias	Low risk	No other sources of bias were identified