Sunshine 1983.

Methods	Randomised, double blind, 3 parallel groups. Single oral dose Medication administered when baseline pain reached a moderate to severe intensity Pain assessed at 0, 30, 60 mins, then hourly to 6 hours
Participants	Various surgical procedures including cholecystectomy, appendectomy, gynaecological operations, Cesarian section N = 120 M = 23, F = 97 Mean age 23 years
Interventions	Codeine 60 mg, n = 40 Propiram fumarate 50 mg, n = 41 Placebo, n = 39
Outcomes	PI: standard 4 point scale PR: standard 5 point scale Use of rescue medication Adverse events Withdrawals
Notes	Oxford Qualtiy Score: R2, DB2, W1. Total = 5 Rescue medication allowed after 1 h
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	"randomized by a computer programme"
Allocation concealment?	Unclear risk	Not described
Blinding? All outcomes	Low risk	Capsule "was identical in appearance and packaging"