Laitinen 1981.

Methods	Randomised controlled trial comparing adverse effects and efficacy of scopolamine, scopolamine + ephedrine and placebo for preventing seasickness
Participants	30 male naval cadets aged 20 to 24 years. Participants with heart disease, hypertension, central nervous system disease, untreated angle closure glaucoma or prostate hypertrophy were excluded.
Interventions	Gelatinous capsules of either scopolamine hydrobromide (0.3 mg), scopolamine hydrobromide + ephedrine hydrochloride (25 mg), or placebo administered 3 times a day at 5 to 6‐hour intervals over 5 days for prophylactic treatment of seasickness during crossing of Baltic and North Seas
Outcomes	Subjective grading of efficacy of treatment and side effects
Notes	No alcohol or central nervous depressants were allowed during the study. Participants were provided with 3 suppositories of 100 mg pyridoxine hydrochloride as supplementary medication if required Schulz rating: randomisation A; allocation concealment B; selection bias B; blinding A
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear