Motion sickness medicines
Cochrane reviews found the scopolamine patch and older antihistamines such as dimenhydrinate prevented motion sickness more than placebo, about 40% against 25% for antihistamines, with no clear difference between them. For acute vertigo, antihistamines eased symptoms at 2 hours but not over weeks. Drowsiness and dry mouth were very common, and meclizine was linked to falls.
Add to Bio HackChecked 2026-11-14
- Status
- Meclizine (Bonine, Dramamine Less Drowsy) and dimenhydrinate (Dramamine) are sold over the counter in the US under Drug Facts labels to prevent and treat motion sickness. Meclizine is also a prescription drug, labeled for vertigo from diseases of the vestibular system in adults. The scopolamine patch (Transderm Scop) is prescription only, labeled in adults to prevent nausea and vomiting from motion sickness and after surgery.
- Also called
- meclizine, meclozine, Bonine, Antivert, Dramamine Less Drowsy, dimenhydrinate, Dramamine, Gravol, scopolamine, hyoscine, scopolamine patch, Transderm Scop, seasickness pills, car sickness, travel sickness
- Taken for
- motion sickness, seasickness, car sickness, air sickness, nausea and vomiting with travel, vertigo, dizziness, inner ear problems, nausea after surgery
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help2
- ModerateShown to prevent motion sickness under natural conditions in susceptible adults, 40% symptom-free against 25% on placebo, with first-generation antihistamines.Very common
- ModerateShown to prevent motion sickness more than placebo in a Cochrane review of 14 small trials. It did not clearly differ from antihistamines.
Reported risks10
- ModerateShown to cause drowsiness more often than placebo, 66% against 44% with first-generation antihistamines in motion sickness trials. The labels warn about driving.Very common
- ModerateThe label reports dry mouth in about two thirds of motion sickness users, and in 29% against 16% on placebo after surgery.Very common
- LimitedThe label reports blurred vision and wide pupils, mydriasis in 4% against none on placebo, and lists angle-closure glaucoma as a contraindication.Common
- LimitedThe label reports agitation in 6% against 4% on placebo, and post-marketing cases of acute psychosis, hallucinations and seizures, with older adults and children more sensitive.Common
- LimitedLinked to injurious falls in a large claims study, at about 2.5 to 3 times the risk within 60 days of a meclizine prescription for dizziness.Common
- LimitedThe label warns that stopping the patch, usually after several days, can cause dizziness, nausea, vomiting, headache and confusion starting a day or more later.How often is not known
- LimitedThe label warns of hyperthermia, including fatal cases, trouble urinating, slowed gut movement, and skin burns if the patch is worn during an MRI.How often is not known
- LimitedLinked to dementia in a cohort of older adults with the heaviest long-term use of strong anticholinergics, a class that includes first-generation antihistamines.How often is not known
- LimitedCase reports: heavy dimenhydrinate use, above 100 mg a day, has been followed by intoxication, psychosis, seizures, dependence and withdrawal, more often in people with psychiatric disorders.How often is not known
- LimitedThe labels warn that alcohol, sedatives and tranquilizers add to drowsiness, and that scopolamine with other anticholinergic drugs raises side effects.How often is not known
What people take it for, and what was found
Shown to help2
Preventing motion sickness, antihistamines (dimenhydrinate and others)
Shown to prevent motion sickness under natural conditions in susceptible adults, 40% symptom-free against 25% on placebo, with first-generation antihistamines.
Compared with placebo or no treatment [1]
The numbers and sources
- How common
- Very common: more than 1 in 10 people.
- Effect
- At sea, in the air or on land, antihistamines prevented motion sickness symptoms in 40% against 25% on placebo (RR 1.81, 95% CI 1.23 to 2.66, 3 studies, 240 participants, moderate certainty). In rotating-chair experiments the effect was very uncertain (SMD 0.32, 95% CI -0.18 to 0.83). No study tested treating symptoms that had already started [1].
- Population
- 658 participants aged 16 to 55 in 9 randomized trials, 6 under natural conditions [1].
- Sources
- [1]
- Caveats
- The natural-condition trials tested only cinnarizine, which is not sold in the US, and dimenhydrinate, so meclizine was not among them. No trial clearly studied children [1].
Preventing motion sickness, the scopolamine patch and other scopolamine forms
Shown to prevent motion sickness more than placebo in a Cochrane review of 14 small trials. It did not clearly differ from antihistamines.
Compared with placebo [2]; antihistamines, methscopolamine and cinnarizine [2][1]
The numbers and sources
- Effect
- Scopolamine, by patch, tablet, solution or injection, prevented symptoms more often than placebo. It was superior to methscopolamine and equivalent to antihistamines, and comparisons with cinnarizine were equivocal [2]. In the antihistamine review, symptoms were prevented in 81% on scopolamine and 71% on antihistamines (RR 0.89, 95% CI 0.68 to 1.16, 2 studies, 71 participants, very low certainty) [1]. No trial tested scopolamine for symptoms that had already started [2].
- Population
- 1,025 participants in 14 randomized trials [2]; 71 participants in 2 trials [1].
- Sources
- [2], [1]
- Caveats
- Studies were generally small and of varying quality [2]. The abstract gives no pooled placebo effect size [2].
Mixed results1
Vertigo and dizziness
Shown to ease acute vertigo at 2 hours with one antihistamine dose, more than a benzodiazepine. Daily use was not shown to beat placebo at 1 week or 1 month.
Compared with benzodiazepines, other active drugs and placebo [3]; diazepam [4]; placebo and transdermal scopolamine [5]
The numbers and sources
- Effect
- In 7 trials with 802 participants, single-dose antihistamines improved 100-point vertigo scores at 2 hours by 16.1 points more than benzodiazepines (95% CI 7.2 to 25.0), and did not differ from other active comparators (2.7 points). At 1 week and 1 month, neither daily antihistamines nor benzodiazepines were reported better than placebo [3]. In an emergency department trial, oral meclizine 25 mg and diazepam 5 mg improved vertigo scores by 40 and 36 points at 60 minutes, not significantly different [4]. In induced vertigo in 12 healthy volunteers, meclizine did not differ from placebo on day 1 and eased symptoms on day 7, while scopolamine eased them on both days [5].
- Population
- 1,586 participants with acute vertigo in 17 randomized trials [3]; 40 adults with acute peripheral vertigo [4]; 12 healthy volunteers with caloric-induced vertigo [5].
- Sources
- [3], [4], [5]
- Caveats
- The 1-week and 1-month trials had high risk of bias [3]. The meclizine label indication is for vertigo from vestibular disease in adults [6].
Doses studied
The dimenhydrinate label directs 50 to 100 mg every 4 to 6 hours for adults and children 12 and over, no more than 400 mg in 24 hours, with the first dose half an hour to an hour before travel, and smaller doses from age 2 [7]. The Bonine meclizine label directs 25 to 50 mg once daily, an hour before travel, from age 12 [8]. The prescription meclizine label lists 25 to 100 mg a day in divided doses for vertigo [6]. The scopolamine patch delivers about 1 mg over 3 days, applied behind the ear at least 4 hours before it is needed [9]. The emergency department vertigo trial used a single 25 mg dose of meclizine [4].
Risks
Reported risks10
Drowsiness and sedation
Shown to cause drowsiness more often than placebo, 66% against 44% with first-generation antihistamines in motion sickness trials. The labels warn about driving.
The numbers and sources
- How common
- Very common: more than 1 in 10 people.
- Effect
- Sedation occurred in 66% on antihistamines and 44% on placebo (RR 1.51, 95% CI 1.12 to 2.02, 2 studies, 190 participants, low certainty). Blurred vision (14% against 12.5%) and impaired cognition (29% against 33%) did not differ [1]. Scopolamine was no more likely than other agents to cause drowsiness, blurred vision or dizziness [2]. In the scopolamine label's motion sickness trials, drowsiness affected less than one sixth [9]. The OTC labels say marked drowsiness may occur and to take care when driving [7][8].
- Population
- 190 participants in 2 trials [1]; 14 trials [2]; label trials [9].
- Sources
- [1], [2], [9], [7], [8]
- Caveats
- The pooled sedation data are for cinnarizine and dimenhydrinate [1]. In induced vertigo, drowsiness was greater on meclizine than on the scopolamine patch [5].
Dry mouth with the scopolamine patch
The label reports dry mouth in about two thirds of motion sickness users, and in 29% against 16% on placebo after surgery.
The numbers and sources
- How common
- Very common: more than 1 in 10 people.
- Effect
- In motion sickness trials, dry mouth was the most common adverse reaction, in about two thirds of users. In trials for nausea after surgery, dry mouth occurred in 29% on the patch and 16% on placebo, dizziness 12% against 7% and somnolence 8% against 4% [9]. Dry mouth was more likely with scopolamine than with methscopolamine or cinnarizine [2].
- Population
- 461 patch and 457 placebo surgical patients [9]; label motion sickness trials [9]; 14 trials [2].
- Sources
- [9], [2]
- Caveats
- The placebo comparison is from surgical patients, not travelers.
Blurred vision, wide pupils and angle-closure glaucoma with scopolamine
The label reports blurred vision and wide pupils, mydriasis in 4% against none on placebo, and lists angle-closure glaucoma as a contraindication.
The numbers and sources
- How common
- Common: between 1 in 100 and 1 in 10 people.
- Effect
- Visual impairment occurred in 5% on the patch and 3% on placebo, and mydriasis in 4% against 0%. The label states scopolamine's pupil-widening effect may raise eye pressure and cause acute angle-closure glaucoma, and says to remove the patch if symptoms develop [9]. The OTC antihistamine labels say to ask a doctor first with glaucoma [7][8].
- Population
- 918 surgical patients in label trials, plus post-marketing reports [9].
- Sources
- [9], [7], [8]
- Caveats
- The rates come from post-surgery trials. Glaucoma cases come from post-marketing reports without a rate [9].
Confusion, agitation and hallucinations with scopolamine
The label reports agitation in 6% against 4% on placebo, and post-marketing cases of acute psychosis, hallucinations and seizures, with older adults and children more sensitive.
The numbers and sources
- How common
- Common: between 1 in 100 and 1 in 10 people.
- Effect
- Agitation occurred in 6% on the patch and 4% on placebo, and confusion in 4% against 3%. The label warns scopolamine can worsen psychosis and cause acute toxic psychosis, hallucinations, paranoia and seizures, and states elderly and pediatric patients may be more sensitive. Its safety and effectiveness in children have not been established [9].
- Population
- 918 surgical patients in label trials, plus post-marketing reports [9].
- Sources
- [9]
- Caveats
- The severe reactions are from post-marketing reports with no rate [9].
Falls with meclizine
Linked to injurious falls in a large claims study, at about 2.5 to 3 times the risk within 60 days of a meclizine prescription for dizziness.
The numbers and sources
- How common
- Common: between 1 in 100 and 1 in 10 people.
- Effect
- Of 805,454 adults newly diagnosed with dizziness, 8% received meclizine, and 9% of them had an injurious fall. A filled prescription was linked to falls in people aged 18 to 64 (HR 2.94, 95% CI 2.81 to 3.08) and 65 or older (HR 2.54, 95% CI 2.42 to 2.66) [10].
- Population
- 805,454 US adults with commercial or Medicare Advantage insurance, 2006 to 2015 [10].
- Sources
- [10]
- Caveats
- Observational. People given meclizine may have had worse dizziness, which itself raises fall risk [10].
Symptoms after removing the patch
The label warns that stopping the patch, usually after several days, can cause dizziness, nausea, vomiting, headache and confusion starting a day or more later.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- The label lists disturbances of equilibrium, dizziness, nausea, vomiting, abdominal cramps, sweating, headache, mental confusion, muscle weakness, slow heart rate and low blood pressure after discontinuation, generally starting 24 hours or more after removal [9].
- Population
- Labeling statement from post-marketing experience [9].
- Sources
- [9]
- Caveats
- No rate is given.
Overheating, urinary retention and MRI burns with the patch
The label warns of hyperthermia, including fatal cases, trouble urinating, slowed gut movement, and skin burns if the patch is worn during an MRI.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Post-marketing reports include serious hyperthermia in adults and children, some fatal, as scopolamine raises core temperature and reduces sweating. The label states scopolamine can decrease gut motility and cause urinary retention. The patch has an aluminized membrane, and skin burns have been reported during MRI scans [9]. The OTC antihistamine labels say to ask a doctor first with trouble urinating from an enlarged prostate [7][8].
- Population
- Post-marketing reports summarized in labeling [9].
- Sources
- [9], [7], [8]
- Caveats
- No rates are given.
Dementia with long-term strong anticholinergic use
Linked to dementia in a cohort of older adults with the heaviest long-term use of strong anticholinergics, a class that includes first-generation antihistamines.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Compared with no use, more than 1,095 standardized daily doses over 10 years was linked to dementia (HR 1.54, 95% CI 1.21 to 1.96), with a dose-response trend. Lower cumulative use was not significantly linked. First-generation antihistamines were among the most used classes [11].
- Population
- 3,434 adults aged 65 or older without dementia at entry, followed a mean 7.3 years [11].
- Sources
- [11]
- Caveats
- Observational. The study pooled anticholinergic drugs and does not give results for motion sickness medicines specifically [11].
Misuse and dependence with dimenhydrinate
Case reports: heavy dimenhydrinate use, above 100 mg a day, has been followed by intoxication, psychosis, seizures, dependence and withdrawal, more often in people with psychiatric disorders.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- A review of 24 studies described seizures, psychosis, depression, anticholinergic-type intoxication and withdrawal with dimenhydrinate, and dependence more often in people with concurrent psychiatric disorders. Most studies were case reports or reviews [12].
- Population
- 24 studies, mostly case reports [12].
- Sources
- [12]
- Caveats
- Low-quality evidence with no rate [12].
Interactions with alcohol, sedatives and other anticholinergic drugs
The labels warn that alcohol, sedatives and tranquilizers add to drowsiness, and that scopolamine with other anticholinergic drugs raises side effects.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- The OTC labels say to ask a doctor or pharmacist first if taking sedatives or tranquilizers, and that alcohol, sedatives and tranquilizers may increase drowsiness [7][8]. The scopolamine label lists sedatives, hypnotics, opiates, anxiolytics, alcohol, sedating antihistamines, meclizine, tricyclic antidepressants and muscle relaxants as potentiating its effects, and says it may delay absorption of other oral drugs [9]. The meclizine prescription label notes possible interactions with CYP2D6 inhibitors [6].
- Population
- Labeling statements [6][7][8][9].
- Sources
- [7], [8], [9], [6]
- Caveats
- No rates are given.
Checked, no increase found1
Pregnancy
The labels state epidemiological studies have not linked meclizine or scopolamine in pregnancy to major birth defects. Scopolamine injections were followed by seizures in severe preeclampsia.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- The meclizine label states epidemiological studies have not identified an increased risk of major birth defects, though high oral doses caused malformations in pregnant rats [6]. The scopolamine label states observational studies and post-marketing reports have not identified a drug-associated risk of major birth defects or miscarriage, and that eclamptic seizures followed injected scopolamine in two women with severe preeclampsia [9]. The OTC labels say to ask a doctor before use in pregnancy [7][8].
- Population
- Epidemiological studies and case reports summarized in labeling [6][9].
- Sources
- [6], [9], [7], [8]
- Caveats
- The labels do not give the size of the studies they summarize.
Claims tested and not found
- That taking antihistamines daily speeds recovery from acute vertigo. At 1 week and 1 month, daily antihistamines were not reported better than placebo [3].
- That antihistamines cloud thinking more than placebo during travel. Impaired cognition did not differ, 29% against 33% on placebo, though sedation was more common [1].
Related
Sources
- Karrim N, Byrne R, Magula N, Saman Y. Antihistamines for motion sickness. Cochrane Database of Systematic Reviews. 2022. https://doi.org/10.1002/14651858.cd012715.pub2
- Spinks A, Wasiak J. Scopolamine (hyoscine) for preventing and treating motion sickness. Cochrane Database of Systematic Reviews. 2011. https://doi.org/10.1002/14651858.cd002851.pub4
- Hunter BR, Wang AZ, Bucca AW, et al. Efficacy of Benzodiazepines or Antihistamines for Patients With Acute Vertigo: A Systematic Review and Meta-analysis. JAMA Neurology. 2022. https://doi.org/10.1001/jamaneurol.2022.1858
- Shih RD, Walsh B, Eskin B, et al. Diazepam and Meclizine Are Equally Effective in the Treatment of Vertigo: An Emergency Department Randomized Double-Blind Placebo-Controlled Trial. The Journal of Emergency Medicine. 2017. https://doi.org/10.1016/j.jemermed.2016.09.016
- Schmitt LG, Shaw JE. Alleviation of induced vertigo. Therapy with transdermal scopolamine and oral meclizine. Archives of Otolaryngology-Head & Neck Surgery. 1986. https://doi.org/10.1001/archotol.1986.03780010090017
- U.S. Food and Drug Administration. Meclizine hydrochloride tablets (RemedyRepack), prescribing information. 2026. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d53bf04e-5cfc-4974-9b24-2cce545d1bd0
- U.S. Food and Drug Administration. DRAMAMINE (dimenhydrinate) chewable tablets, drug facts label. 2026. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=76166156-bce1-492f-833e-6bbd07859c3f
- U.S. Food and Drug Administration. BONINE (meclizine hydrochloride) chewable tablets, drug facts label. 2026. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0b2ea6b8-b342-4940-8922-898758fbeb31
- U.S. Food and Drug Administration. TRANSDERM SCOP (scopolamine) transdermal system, prescribing information. 2026. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=b877a694-a1d0-4280-937a-a06820b12a88
- Adams ME, Karaca-Mandic P, Marmor S. Meclizine Use and Subsequent Falls Among Patients With Dizziness. JAMA Otolaryngology-Head & Neck Surgery. 2025. https://doi.org/10.1001/jamaoto.2025.2052
- Gray SL, Anderson ML, Dublin S, et al. Cumulative use of strong anticholinergics and incident dementia: a prospective cohort study. JAMA Internal Medicine. 2015. https://doi.org/10.1001/jamainternmed.2014.7663
- Bahji A, Kasurak E, Sterling M, Good L. Misuse and dependence of dimenhydrinate: A mixed studies systematic review. Journal of Psychiatric Research. 2021. https://doi.org/10.1016/j.jpsychires.2020.10.032