What medication is recommended for motion sickness in children?

Motion Sickness Treatment in Children

For children with motion sickness, dimenhydrinate is the recommended first-line medication, administered at 1.25 mg/kg body weight (or 37.5 mg/m² body surface area) intramuscularly or orally four times daily, with a maximum daily dose not exceeding 300 mg. 1

Age-Specific Safety Considerations

Critical safety warning: Children under 6 years of age should not receive over-the-counter antihistamines for motion sickness due to documented toxicity risks and safety concerns. 2 Between 1969 and 2006, there were 69 fatalities associated with antihistamines in children under 6 years, with 41 deaths occurring in children under 2 years. 2

Medication Options by Age Group

Children ≥6 Years

• Dimenhydrinate is FDA-approved for prevention and treatment of motion sickness-related nausea, vomiting, and vertigo 1
• Dosing: 1.25 mg/kg body weight or 37.5 mg/m² body surface area four times daily 1
• Maximum daily dose: 300 mg 1
• Expected duration of symptom control: approximately 4 hours per 50 mg dose 1

Children <6 Years

• Pharmacological treatment is not recommended due to safety concerns 2
• Non-pharmacological approaches should be prioritized: distraction techniques, audio-visual entertainment, and relaxation methods 2

Mechanism and Efficacy

Antihistamines work by suppressing the central emetic center to relieve nausea and vomiting associated with motion sickness. 3, 4 Under naturally occurring motion conditions, first-generation antihistamines prevent motion sickness symptoms in approximately 40% of susceptible individuals compared to 25% with placebo (moderate-certainty evidence). 5

Administration Guidelines

Intramuscular Route

• Each milliliter (50 mg) of solution is injected as needed 1
• Preferred when oral administration is impractical 1

Intravenous Route (if necessary)

• Each milliliter (50 mg) must be diluted in 10 mL of 0.9% Sodium Chloride Injection 1
• Inject over a period of 2 minutes 1

Oral Route

• Can be taken with or without food 1
• Most practical for routine prevention 1

Important Adverse Effects

Sedation is the most common side effect, occurring in approximately 66% of patients taking antihistamines compared to 44% with placebo. 5 This may be accompanied by drowsiness, which can actually be desirable in some travel situations. 1

Other potential adverse effects include:

• Blurred vision (14% vs 12.5% placebo) 5
• Impaired cognition (29% vs 33% placebo) 5
• Drowsiness and malaise 6

Critical Pitfalls to Avoid

Do not combine multiple motion sickness medications, as this can lead to overdose errors and increased risk of adverse effects. 2

Avoid long-term use of vestibular suppressant medications, as they interfere with central compensation in peripheral vestibular conditions and prevent natural adaptation to motion. 3, 2

Never administer aspirin or aspirin-containing products (such as bismuth subsalicylate) to children ≤18 years with nausea/vomiting due to the risk of Reye's syndrome. 3

Timing of Administration

For optimal prevention, antihistamines should be administered before the anticipated motion exposure rather than after symptoms develop. 6, 7 The medication is most effective when given prophylactically, as treatment of established symptoms is less successful. 6

Behavioral Strategies to Enhance Medication Efficacy

When combined with pharmacotherapy, these strategies improve outcomes:

• Position child in the most stable part of the vehicle (front seat if age-appropriate, middle of boat) 6
• Have child watch the true visual horizon 6
• Encourage lying down with eyes closed 6
• Minimize exposure to difficult travel conditions 6
• Reduce other sources of physical and emotional discomfort 6