What are the recommended prescription medications for motion sickness available in Canada?

Recommended Motion Sickness Medications Available in Canada by Prescription

Transdermal scopolamine (Transderm-V) is the most effective prescription medication for motion sickness prevention available in Canada, with clinical studies showing 60-80% reduction in motion sickness symptoms compared to placebo. 1

First-Line Therapy: Scopolamine

Transdermal Scopolamine

• Formulation: Transdermal patch delivering approximately 1 mg over 3 days 2
• Dosing: Apply one patch to hairless area behind ear at least 4-6 hours before travel (ideally 8-12 hours for optimal effect) 2, 3
• Duration: Effective for up to 3 days; for longer trips, remove and apply new patch behind opposite ear 2
• Mechanism: Anticholinergic that blocks muscarinic receptors in the vestibular apparatus and vomiting center
• Efficacy: 60-80% reduction in motion sickness incidence and severity compared to placebo 3

Clinical Considerations for Scopolamine

• Advantages:

  • Longer duration of action (72 hours) compared to oral medications
  • Lower incidence of sedation compared to antihistamines 3
  • Steady drug delivery avoids peaks and troughs of oral dosing
  • Protective plasma concentration (50 pg/mL) achieved after 6 hours 3

• Contraindications: 2

  • Angle-closure glaucoma
  • Hypersensitivity to scopolamine or belladonna alkaloids

• Common Side Effects: 2, 3

  • Dry mouth (50-60% of users)
  • Drowsiness (up to 20%)
  • Blurred vision (transient)
  • Contact dermatitis at application site (10%)

• Serious Adverse Effects (rare): 2

  • Acute angle-closure glaucoma
  • Neuropsychiatric reactions (confusion, hallucinations)
  • Seizures (in predisposed individuals)

Second-Line Therapies

First-Generation Antihistamines

• Dimenhydrinate (Gravol):

  • Dosing: 50-100 mg every 4-6 hours (max 400 mg/day) 4
  • Efficacy: Less effective than scopolamine but superior to placebo 4, 5
  • Side Effects: Higher incidence of sedation compared to scopolamine 3

• Promethazine:

  • Dosing: 12.5-25 mg orally or rectally every 4-6 hours 6
  • Side Effects: CNS depression, anticholinergic effects, extrapyramidal symptoms 6

Combination Therapy

For severe cases or when single agents are ineffective:

• Scopolamine + Antihistamine: May provide enhanced efficacy but with increased risk of side effects
• Scopolamine + Oral Scopolamine: For faster onset (apply patch + 0.3-0.6 mg oral dose 1 hour before travel) 3

Patient Selection Algorithm

1. For long journeys (>6 hours) or when oral therapy is ineffective:

   • Transdermal scopolamine (first-line)

2. For shorter journeys or patients with contraindications to scopolamine:

   • First-generation antihistamines (dimenhydrinate, promethazine)

3. For patients with history of severe motion sickness:

   • Consider combination therapy

4. For patients with glaucoma, prostatic hypertrophy, or cognitive concerns:

   • Avoid scopolamine; use antihistamines with caution

Important Clinical Pearls

• Apply scopolamine patch at least 4-6 hours before travel (ideally 8-12 hours for optimal effect) 3
• Wash hands thoroughly after application to avoid transferring medication to eyes 2
• Approximately 20-30% of patients may not achieve protective plasma concentrations with transdermal scopolamine 3
• Nonsedating antihistamines, ondansetron, and ginger root are not effective for motion sickness prevention 7
• Elderly patients and children are more sensitive to neurological and psychiatric effects of scopolamine 2
• For patients requiring rapid onset protection, consider combination of transdermal patch plus oral medication 3

Transdermal scopolamine remains the gold standard prescription medication for motion sickness prevention in Canada, offering superior efficacy with a favorable side effect profile compared to other available options 3, 1.