Antiemetics: Putting a Stop to Motion Sickness

Motion sickness is easier to prevent than treat but OTC options are available.

Motion sickness is defined as a short-lived response to abnormal motion stimuli or contradictory spatial sensory information, which may result in nausea, vomiting, and dizziness.¹ Anyone can experience motion sickness, but some people are more susceptible to it than others.

Many individuals experience motion sickness when traveling by boat, while others may experience it traveling via car, train, or airplane.^2,3 Some people have even reported episodes of motion sickness while viewing 3D movies.² Those suffering from motion sickness generally experience an unpleasant feeling of malaise.⁴ The condition occurs most commonly in women.⁴

The nausea and vomiting associated with motion sickness is the result of overstimulation of the labyrinth (inner ear) apparatus.³ Preventing or finding immediate relief for the symptoms of motion sickness is a top priority for those affected by it.

Treatments for Motion Sickness

Pharmacologic Products

The nonprescription products currently available for the prevention and treatment of motion sickness include various antihistamine products.³ First-generation antihistamines in particular act on the part of the brain that controls nausea and vomiting. Nonprescription antihistamines indicated for the prevention and treatment of motion sickness include meclizine, cyclizine, dimenhydrinate, and diphenhydramine.

Prestige Brands Inc has a new formulation of Dramamine (dimenhydrinate) available in grape-flavored chewable tablets for children aged 2 to 12 years. For antiemetic products to be effective, patients should be advised to take them at least 30 to 60 minutes before travel to allow adequate time for onset of action and continue taking them during travel.³

Nonpharmacologic Options

There are also several nonpharmacologic products available, including Sea-Band, Bio Band, and Relief Band NST wristbands, that employ the principles of acupressure to prevent or manage nausea and vomiting.³ Patients experiencing severe motion sickness should be encouraged to seek further medical evaluation.

Many experts agree that motion sickness is easier to prevent than treat.³ The sidebar presents simple measures that pharmacists can share with patients to help prevent motion sickness.

During counseling, patients should be advised of possible adverse effects from the products described, such as drowsiness, blurred vision, dry mouth, and urinary retention, and should be advised to exercise caution until they are aware of how these agents affect them.³ In addition, patients with certain medical conditions such as asthma, narrow-angle glaucoma, or benign prostatic hypertrophy should be advised not to use these products unless directed to do so by their physician.³

Patients should be cautioned that an increased sedative effect may occur when these products are used in conjunction with central nervous system depressants, such as alcohol, tranquilizers, and hypnotics.³ Patients should also be advised that use of antihistamines by children may cause paradoxical stimulation, and use by geriatric patients may cause agitation and confusion.³

Most cases of motion sickness are mild and are amenable to self-treatment. Individuals with chronic motion sickness, however, should be referred to a physician to determine the best options for managing their condition. Prior to recommending any of these nonprescription products, it is imperative that pharmacists ascertain whether self-treatment is appropriate. Pharmacists should ensure that patients clearly understand the proper use of these OTC products and should also recommend nonpharmacologic means of preventing or reducing the incidence of motion sickness.

Pharmacists are also in a unique position to assist in product selection for pediatric patients, because antihistamines such as dimenhydrinate and diphenhydramine should not be taken by children younger than 2 years. In addition, cyclizine should not be used by children younger than 6 years, and meclizine should not be used by children younger than 12 years.³

Final Thought

Prior to recommending any products, pharmacists should screen for possible contraindications and drug interactions in patients with pre-existing medical conditions and those currently taking other medications. These patients should be encouraged to consult their primary health care provider prior to using any of these products and to discuss other options for preventing motion sickness, including prescription medications.

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.

References

• Motion sickness in children: a normal response to ‘abnormal’ stimuli. Medscape website. www.medscape.com/viewarticle/406451.
• 3 D movies: thrills and ills. Medline Plus website. www.nlm.nih.gov/medlineplus/news/fullstory_126999.html.
• Ferreri SP. Nausea and vomiting. In: Krinsky D, Berardi R, Ferreri S, et al, eds. Handbook of Nonprescription Drugs. 17th ed. Washington, DC: American Pharmacists Association; 2012.
• Brainard A. Motion sickness. Medscape website. http://emedicine.medscape.com/article/2060606-overview.
• Dizziness and motion sickness. American Academy of Otolaryngology website. www.entnet.org/HealthInformation/dizzinessMotionSickness.cfm.