Ajmera 2006.

Methods	Study design: randomised controlled trial. Allocation generation: random allocation. Allocation concealment: not done. Blinding: open trial. Loss to follow‐up: intervention: 3.3% control: 2.6%.
Participants	Total number of participants randomised: 225. Inclusion criteria: primi‐ and multigravidas. Gestational age 37‐41 weeks, singleton pregnancy, cephalic presentation, spontaneous labour, no obstetric or medical complications. Exclusion criteria: none specified.
Interventions	Intervention: 1. Drotaverine hydrochloride 40 mg IMI, administered in active phase at 3 cm dilatation and repeated every 2 h for max 3 doses. n = 75. 2. Valethamate bromide 8 mg IVI, administered in active phase, at 3 cm dilatation, repeated every half an hour for a max of 3 doses. n = 75. Control: No medication. n = 75.
Outcomes	Primary outcomes: 1. Duration of first stage of labour (from 3 cm to full dilatation of cervix) 2. Duration of second and third stage of labour. 3. Mode of delivery. Secondary outcomes: Neonatal and maternal adverse events.
Notes	Ethics: ethical approval not mentioned, informed consent not mentioned. Location: India, Mumbai. No contact details.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Random allocation ‐ not clearly described.
Allocation concealment (selection bias)	High risk	This is an open trial.
Blinding of participants and personnel (performance bias) All outcomes	High risk	This is an open trial.
Blinding of outcome assessment (detection bias) All outcomes	High risk	This is an open trial.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data, all participants accounted for.
Selective reporting (reporting bias)	Unclear risk	Primary outcomes: 1. Duration of labour: adequately reported. 2. Mode of delivery: adequately reported. Secondary outcomes: 1. Maternal adverse events: adequately reported. 2. Neonatal adverse events: Apgar scores not reported.
Other bias	High risk	Authors did not mention spontaneous or artificial rupture of membranes, the use of other drugs to augment labour or analgesia. All these are known to influence the duration of labour and could have biased results. No contact details are present. Drug company sponsorship: not mentioned.