Van Staden 1971.

Methods	RCT, Double blind, crossover design, general anaesthetic. Self‐assessed at 1 hour then hourly for 8 hrs. Medication given when pain of moderate to severe intensity.
Participants	Gynaecological surgery n = 91 Age: adult
Interventions	Dextropropoxyphene HCl 65 mg, n = 26 Placebo, n = 29
Outcomes	PI (4 point scale) standard PR measured as PID (pain intensity difference) Dextropropoxyphene was not significantly better than placebo (P not given). SPID at 4 hrs: Dextropropoxyphene HCl 65 mg: 1.64 Placebo: 1.57
Notes	Remedication allowed after 1 hour if no pain relief. PR scored as zero for all subsequent time points. 80 patients data were analysed. 11 excluded: 6 violated protocol, 2 vomited, 3 had insufficient pain. Authors reported a significant difference from placebo for CNS adverse events (P= 0.05). None serious & no withdrawals. Dextropropoxyphene HCl 65 mg: 19/25 patients reported 27 adverse events. Dextropropoxyphene HCl 130 mg:23/25 patients reported 34 adverse events. Placebo:10/25 patients reported 12 adverse events. QS = 4
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

QS = quality score
 PR ‐ pain relief
 PI ‐ pain intensity
 CNS ‐ central nervous system