Treatment for Motion Sickness
For adults, scopolamine transdermal patch applied at least 4 hours before travel is the first-line treatment for motion sickness prevention, with first-generation antihistamines like meclizine (12.5-25 mg three times daily) or dimenhydrinate as effective alternatives. 1, 2
First-Line Pharmacological Treatment
Scopolamine Transdermal System
- Apply one 1.5 mg transdermal patch to the hairless area behind the ear at least 4 hours before anticipated motion exposure (FDA labeling specifies minimum 4 hours, though some guidelines suggest 6-8 hours for optimal effect). 2, 1
- Each patch delivers approximately 1 mg of scopolamine over 3 days and can be replaced with a new patch behind the opposite ear if treatment is needed beyond 3 days. 2
- Scopolamine works by blocking acetylcholine, a widespread CNS neurotransmitter, thereby reducing the neural mismatch that causes motion sickness. 1
- Critical application instructions: Wash hands thoroughly with soap and water immediately after applying the patch to prevent accidental eye contamination, which can cause pupil dilation and blurred vision. 2
First-Generation Antihistamines (Alternative or Second-Line)
- Meclizine 12.5-25 mg three times daily is recommended for patients who cannot use scopolamine due to contraindications or side effects. 1
- Dimenhydrinate is another effective first-generation antihistamine option. 3
- Antihistamines suppress the central emetic center to relieve nausea and vomiting, with approximately 40% prevention efficacy under natural conditions compared to 25% with placebo. 1, 3
- These medications should be taken before travel begins for optimal prevention. 4
Promethazine for Severe Cases
- Promethazine 12.5-25 mg is reserved for severe cases requiring rapid onset of action, though it carries risks of hypotension, respiratory depression, and extrapyramidal effects. 1
Combination Therapy for Severe Symptoms
- Scopolamine transdermal patch plus meclizine can be used together when severe symptoms require combination therapy, providing complementary mechanisms of action (anticholinergic plus antihistaminic). 1
Special Population Considerations
Children
- Children under 6 years should NOT receive over-the-counter antihistamines for motion sickness due to safety concerns and reported fatalities (69 deaths between 1969-2006, with 41 in children under 2 years). 5
- For children who can take antihistamines (≥6 years), monitor closely for paradoxical behavioral disinhibition and sedation (occurs in approximately 66% of patients). 5
- Non-pharmacological approaches should be prioritized first in children: distraction techniques, audio-visual entertainment, and relaxation methods. 5
Elderly Patients
- Elderly patients are at higher risk for anticholinergic side effects (confusion, falls, cognitive impairment) and require close monitoring when using scopolamine or antihistamines. 1
- Anticholinergic medications are an independent risk factor for falls in this population. 1
Contraindications and Important Warnings
Absolute Contraindications
- Angle-closure glaucoma (scopolamine's mydriatic effect can precipitate acute angle-closure glaucoma). 2
- Hypersensitivity to scopolamine, belladonna alkaloids, or antihistamines. 2
Serious Warnings
- Neuropsychiatric effects: Scopolamine can cause acute toxic psychosis, agitation, hallucinations, paranoia, delusions, and seizures—remove patch immediately if these occur. 2
- Monitor patients with open-angle glaucoma for increased intraocular pressure and adjust glaucoma therapy as needed. 2
- Patients should immediately remove the patch and seek care if experiencing eye pain, blurred vision, visual halos, or red eyes. 2
Common Adverse Effects
Scopolamine
- Dry mouth, drowsiness, disorientation, confusion, and blurred vision are most common. 2
- Temporary pupil dilation if patch contacts eyes. 2
- Withdrawal symptoms can occur 24+ hours after patch removal (dizziness, nausea, vomiting, confusion, muscle weakness, low heart rate/blood pressure) if used for several days. 2
Antihistamines
- Sedation occurs in approximately 66% of patients (more likely than placebo: 66% vs 44%). 3, 5
- Blurred vision and impaired cognition may occur but show little difference compared to placebo. 3
Critical Pitfalls to Avoid
- Do NOT use vestibular suppressants long-term as they interfere with natural vestibular compensation and adaptation to motion. 1, 5
- Do NOT cut the transdermal patch as this alters drug delivery. 2
- Do NOT use benzodiazepines for motion sickness—they lack efficacy and carry significant harm potential. 1
- Avoid aspirin in children ≤18 years with nausea/vomiting due to Reye's syndrome risk. 5
- Second-generation (non-sedating) antihistamines, ondansetron, and ginger root are NOT effective for motion sickness prevention or treatment. 4
Medications That Do NOT Work
- Second-generation antihistamines (loratadine, cetirizine, etc.) are ineffective. 4
- Ondansetron is ineffective. 4
- Ginger root is ineffective. 4