Prevention of Vomiting During Travel
For motion sickness prevention during travel, first-generation antihistamines (such as dimenhydrinate or cinnarizine) are the most effective pharmacologic option, reducing symptoms by approximately 40% compared to 25% with placebo. 1
Recommended Antihistamines for Motion Sickness
- Dimenhydrinate is a first-generation antihistamine with proven efficacy for preventing motion sickness under natural travel conditions (air, sea, and land transportation) 1
- Cinnarizine is another effective first-generation antihistamine option for motion sickness prevention 1
- These medications should be taken prophylactically before travel begins, as they are most effective when used preventively rather than for treating established symptoms 1
Important Caveats About Antihistamines
- Sedation is a common side effect - antihistamines increase sedation risk by approximately 50% compared to placebo (66% vs 44%), which may impair driving or operating machinery 1
- Antihistamines may cause little or no difference in blurred vision (14% vs 12.5% with placebo) or impaired cognition (29% vs 33% with placebo) 1
- The evidence for antihistamine efficacy is strongest for first-generation agents; there is insufficient data on second-generation antihistamines for motion sickness 1
Alternative Options
- Scopolamine (anticholinergic) is another option, though the evidence comparing it to antihistamines is very uncertain, with scopolamine preventing symptoms in 81% vs 71% with antihistamines 1
- Acupuncture has been studied but evidence is very uncertain regarding its effectiveness compared to antihistamines 1
Critical Distinction: Motion Sickness vs Traveler's Diarrhea
- The question asks about preventing vomiting during travel, which typically refers to motion sickness, not traveler's diarrhea 1
- If the concern is vomiting from traveler's diarrhea (gastroenteritis), the approach is entirely different - antiemetics like ondansetron may be considered for gastroenteritis-related vomiting, though this is primarily studied in children 2
- For traveler's diarrhea prevention and treatment, azithromycin is the preferred antibiotic for moderate-to-severe cases, but this addresses diarrhea rather than motion sickness 3
Practical Implementation
- Take the antihistamine 30-60 minutes before travel begins for optimal prevention 1
- Be aware that sedation may affect your ability to drive or perform tasks requiring alertness 1
- The moderate-certainty evidence supports antihistamine use specifically under natural travel conditions (actual motion during transportation) 1