Antiemetics

Many types of antiemetics can decrease the severity of nausea and vomiting.

Drugs used to treat nausea and vomiting are called antiemetics. Many types of antiemetics can decrease the severity of nausea, although most require a medical evaluation and prescription. Medicines available over-the-counter are mainly recommended for use in motion sickness and cases of mild nausea.

Nausea and vomiting occur for many reasons. Common causes include:

• Motion sickness
• Self-limited illnesses (viruses or food poisoning) that last a few hours to a few days
• Toxins (such as certain medications)

Motion sickness may occur in many settings including travel by car, air, or boat. This may be the best indication for the use of over-the-counter medications for nausea and vomiting associated with riding in a vehicle. Other inner-ear problems that are related to motion sickness can create a feeling of nausea as well.

Viral infections can cause nausea and vomiting, which is often associated with diarrhea. Often, an "outbreak" can be identified with several cases occurring in the same household or community. Food poisoning from either bacteria or viruses can cause similar symptoms. In both situations, the illnesses generally run their course throughout one to two days and resolve without treatment. The very young and very old are at risk for dehydration from these usually minor illnesses.

Medications can cause nausea or vomiting and should be suspected when the symptoms appear within a short time after starting a new medication. Notify your prescribing physician if this happens.

The types of antiemetics used to treat nausea and vomiting include the following:

• Meclizine hydrochloride (Bonine) is an antihistamine that is effective in the treatment of nausea, vomiting, and dizziness associated with motion sickness. Unless recommended by a physician, it should not be taken by people with lung diseases, glaucoma, or those who have difficulty urinating due to an enlarged prostate. Meclizine may cause drowsiness and should not be taken with other sedatives such as alcohol, tranquilizers, or sleeping pills. Due to drowsiness, people using meclizine should not drive or operate dangerous machinery. Meclizine is not recommended in children under 12 or in pregnant or nursing women unless recommended by a doctor.
• Dimenhydrinate (Dramamine) also is an antihistamine. Its use should be limited to motion sickness. It can cause drowsiness and should be avoided in the same situations as Meclizine. Several different formulations of dimenhydrinate are available, including a children's liquid, which should be used according to the directions under the direction of a physician. Dramamine Less Drowsy Formula contains meclizine, like Bonine, and may have fewer sedative side effects. Both meclizine and dimenhydrinate are recommended to be taken about an hour before travel to prevent motion sickness.
• Emetrol is an oral solution designed to soothe the stomach when nausea and vomiting are caused by viral or bacterial infection or overeating. Emetrol contains sugar and phosphoric acid. Diabetics should not use Emetrol without medical supervision because of the concentrated sugar. According to its manufacturer, Emetrol should not be taken for more than five doses in one hour without consulting a physician. Consult a doctor before using this medicine for pregnant or nursing women and young children.
• Bismuth subsalicylate (Pepto-Bismol) is a product containing bismuth subsalicylate, a chemical shown to be effective in relieving nausea and upset stomach. This remedy has a direct effect on the stomach lining and has no known serious side effects. It may cause the darkening of the stool color and the tongue. Pregnant or nursing women should consult their doctors before using bismuth subsalicylate since part of the active ingredient (salicylate) is chemically similar to aspirin, which may harm infants and the fetus. Patients allergic to aspirin or related drugs also should not use bismuth subsalicylate. Use under the direction of a physician if you take anticoagulants (blood thinners) or have diabetes or gout because the salicylate may further promote the anticoagulant effect.

Nausea and vomiting are not diseases but symptoms that can be caused by many conditions.

Several other less common reasons for nausea and vomiting include:

• early stages of pregnancy (nausea occurs in approximately 50%-90% of all pregnancies, vomiting in 25%-55%),
• painful injury,
• postoperative (the period following surgery),
• an emotional or fearful situation,
• gallbladder disease, gallstones or infection (cholecystitis),
• overeating (especially after gastric bypass surgery),
• a reaction to certain smells or odors,
• heart attack (may be the only symptom in some people),
• concussion or head injury,
• brain tumor,
• ulcers or gastritis,
• bulimia or other psychological illnesses, and
• gastroparesis (slow stomach emptying often seen in people with diabetes).

People should consult a doctor if nausea and/or vomiting are persistent or are accompanied by other severe symptoms such as abdominal pain, fever, yellow discoloration of the skin (jaundice), or bleeding. Individuals with severe or ongoing vomiting who have other serious medical problems, are elderly, are very young, or are pregnant or nursing infants should also seek medical attention.