Medications for Sea Sickness in Canada
For sea sickness prevention in Canada, scopolamine transdermal patch is the most effective first-line medication, applied 4-16 hours before sea travel, with antihistamines (dimenhydrinate, meclozine, or cinnarizine) as reasonable alternatives.
First-Line Treatment: Scopolamine Transdermal System
- Scopolamine transdermal patch (1 mg/3 days) is FDA-approved for motion sickness prevention and should be applied to the hairless area behind one ear 4-16 hours before exposure to motion 1
- Transdermal scopolamine demonstrated superior efficacy compared to placebo (p = 0.0001) in preventing motion sickness at sea, with minimal side effects of dry mouth, drowsiness, and blurred vision 2
- The patch delivers approximately 1 mg of scopolamine over 3 days and should not be cut; only one patch should be used at a time 1
- Hands must be washed thoroughly before application and after handling the patch to avoid accidental eye contamination 1
Alternative Antihistamine Options
- Dimenhydrinate (with or without caffeine) is an effective alternative, administered 1.5 hours before motion exposure, though it showed slightly lower efficacy than scopolamine (p = 0.05 vs p = 0.0001) 2
- A comparative study of seven agents found that cinnarizine, cyclizine, dimenhydrinate with caffeine, and meclozine with caffeine all showed similar efficacy, with 4.1-10.2% experiencing vomiting and 16.4-23.5% experiencing malaise across treatment groups 3
- Scopolamine TTS was noted to be slightly less effective and caused more visual problems in this comparative study, though it remains FDA-approved and widely used 3
Important Clinical Considerations
- Scopolamine should be avoided in patients with glaucoma, urinary retention, or gastrointestinal obstruction (standard anticholinergic contraindications based on drug class) 1
- Women are more susceptible to motion sickness than men, with menstruation and pregnancy being predisposing factors 4
- Children aged 2-12 years are most susceptible to motion sickness, though specific pediatric dosing should be carefully calculated 4
- Symptoms typically last no longer than 3 days, even without treatment 4
Medications NOT Recommended
- Ondansetron (5HT3 blocker) showed no statistically significant reduction in seasickness symptoms compared to placebo (Wiker score 2.69 vs 2.81, not significant) and should not be used for sea sickness prevention 5
- The mechanism of nausea in seasickness appears different from toxin-induced nausea, explaining why ondansetron is ineffective 5
Non-Pharmacological Adjunct
- Optokinetic stimulation reeducation can reduce sea sickness by a factor of 2 and may be considered as an adjunctive or alternative approach for patients who cannot tolerate medications 6