Chapter 2The Pre-Travel ConsultationSelf-Treatable Conditions
RISK FOR TRAVELERS
All people can develop motion sickness if given sufficient stimulus. However, people may vary in their susceptibility. Risk factors include:
- Age—children aged 2–12 years are especially susceptible, but infants and toddlers are generally immune.
- Sex—women are more likely to have motion sickness, especially when pregnant, menstruating, or on hormones.
- Migraines—people who get migraine headaches are more prone to motion sickness, especially during a migraine.
- Medication—some prescriptions can worsen the nausea of motion sickness (Table 2-09).
Habituation to motion can be effective and has few long-term adverse side effects; however, as a method for controlling motion sickness, this can be a time-consuming and unpleasant approach. Many patients will prefer medication. A primary side effect of most efficacious medications used for motion sickness is drowsiness, along with other drug-specific side effects. Some medications may interfere with or delay habituation. Because gastric stasis can occur with motion sickness, parenteral delivery may be advantageous.
Antihistamines are the most frequently used and widely available medications for motion sickness. Nonsedating ones appear to be less effective. Antihistamines commonly used for motion sickness include cinnarizine (not currently available in the United States), cyclizine, dimenhydrinate, meclizine, and promethazine (oral and suppository). Other common medications used to treat motion sickness are scopolamine (hyoscine, oral and transdermal), antidopaminergic drugs (such as prochlorperazine), metoclopramide, sympathomimetics, and benzodiazepines. Clinical trials have not shown efficacy for ondansetron in the prevention of nausea associated with motion sickness.
When recommending any of these medications to travelers, providers should make sure that patients understand the risks and benefits, possible undesirable side effects, and potential drug interactions. Some travelers may need to try the medication before travel to see what effect it has. (See also the Self-Treatable Conditions section earlier in this chapter.)
Medications in Children
For children aged 2–12 years, dimenhydrinate (Dramamine), 1–1.5 mg/kg per dose, or diphenhydramine (Benadryl), 0.5–1 mg/kg per dose up to 25 mg, can be given 1 hour before travel and every 6 hours during the trip. Because some children have paradoxical agitation with these medicines, a test dose should be given at home before departure. Antihistamines are not approved by the Food and Drug Administration to treat motion sickness in children. Caregivers should be reminded to always ask a physician, pharmacist, or other clinician if they have any questions about how to use or dose antihistamines in children before they administer the medication. Oversedation of young children with antihistamines can be life-threatening.
Scopolamine can cause dangerous adverse effects in children and should not be used; prochlorperazine and metoclopramide should be used with caution in children.
Medications in Pregnancy
Drugs with the most safety data regarding the treatment of the nausea of pregnancy are the logical first choice. Alphabetical scoring of the safety of medications in pregnancy may not be helpful, and clinicians should review the actual safety data or call the patient’s obstetric provider for suggestions. Web-based information may be found at the websites www.Motherisk.org and www.Reprotox.org.
Table 2-09. Medications that may increase nausea
|Antibiotics||Azithromycin, metronidazole, erythromycin, trimethoprim-sulfamethoxazole|
|Antiparasitics||Albendazole, thiabendazole, iodoquinol, chloroquine, mefloquine|
|Estrogens||Oral contraceptives, estradiol|
|Narcotic analgesics||Codeine, morphine, meperidine|
|Nonsteroidal analgesics||Ibuprophen, naproxen, indomethacin|
|Antidepressants||Fluoxetine, paroxitene, sertraline|
|Bisphosphonates||Alendronate sodium, ibandronate sodium, risedronate sodium|
Nonpharmacologic interventions to prevent or treat motion sickness include:
- Being aware of and avoiding situations that tend to trigger symptoms.
- Optimizing position to reduce motion or motion perception—for example, driving a vehicle instead of riding in it, sitting in the front seat of a car or bus, or sitting over the wing of an aircraft. Cabin location on a cruise ship does not appear to influence the likelihood of motion sickness.
- Reducing sensory input—lying prone, shutting eyes, or looking at the horizon.
- Maintaining hydration by drinking water, eating small meals frequently, and limiting alcoholic and caffeinated beverages.
- Adding distractions—listening to music or using aromatherapy scents such as mint or lavender. Flavored lozenges may also help, in particular ginger-flavored. Lozenges may also function as distractions or, in the case of ginger, may hasten gastric emptying.
- Using acupressure or magnets is advocated by some to prevent or treat nausea, although scientific data on efficacy of these interventions for preventing motion sickness are equivocal.
- Gahlinger PM. Cabin location and the likelihood of motion sickness in cruise ship passengers. J Travel Med. 2000 May–Jun;7(3):120–4.
- Murdin L, Golding J, Bronstein A. Managing motion sickness. BMJ. 2011;343:d7430.
- Priesol AJ. Motion Sickness. Deschler DG, editor. Waltham MA: UpToDate; 2012.
- Takeda N, Morita M, Horii A, Nishiike S, Kitahara T, Uno A. Neural mechanisms of motion sickness. J Med Invest. 2001 Feb;48(1–2):44–59.