Travel to Developing Countries - Travel Precautions

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Motion Sickness

About a third of the population is susceptible to motion sickness, with varying degrees of severity. The cause of motion sickness is still unclear. Some evidence suggests that, in susceptible people, motion triggers signals that the brain interprets as being inharmonious, conflicting with the brain's memory of correct position. It transmits this message to other parts of the body, which respond with sweating, nausea, salivating, and other symptoms of motion sickness. Other theories suggest that motion sickness is triggered by the body's inability to control its own posture and movement.

More women than men experience motion sickness, with one study suggesting that this may be associated with gender differences in the ability to perform spatial tasks. Women appear to be at higher risk just before and during menstruation. Motion sickness may also trigger migraines, even in people who do not ordinarily have them. Alcohol intake increases the risk of vomiting. The following are some remedies tried for motion sickness:

Medications. Prescribed medications include scopolamine in oral form or as a patch (Transderm Scop), which is worn behind the ear and releases the drug slowly. Scopolamine is the most effective drug for motion sickness.

Over-the-counter medications include dimenhydrinate (Dramamine), meclizine (Bonine), and cyclizin (Marezine). Dramamine appears to be the most rapidly effective, although in one study Marezine caused less drowsiness and was more effective at reducing nausea after 3 minutes. Cinnarizine (Stugeron) is used in Europe and appears to be effective with few side effects. It is not available in the US. None of these medications are as effective as prescription drug but may be helpful for 6 - 12 hours. Oral medications should be taken at least an hour before traveling to be effective.

Nearly all the medications used for motion sickness, both prescription and nonprescription, can cause drowsiness, mouth dryness, and blurred vision. Scopolamine can cause heart rhythm disturbances. In one comparison study the scopolamine patch and cinnarizine had the fewest adverse effects on functioning. Dimenhydrinate had the most.