• Antiemetic --Buclizine; Cyclizine; Meclizine
• Antivertigo agent --Meclizine

Buclizine, cyclizine, and meclizine are used to prevent and treat nausea, vomiting, and dizziness associated with motion sickness, and vertigo (dizziness caused by other medical problems).

Some of these preparations are available only with your doctor's prescription. Others are available without a prescription; however, your doctor may have special instructions on the proper dose of the medicine for your medical condition. They are available in the following dosage forms:

Oral
• Buclizine
  • Chewable tablets
• Cyclizine
  • Tablets (U.S.)
• Meclizine
  • Tablets (U.S.)
  • Chewable tablets (U.S. and Canada)

Parenteral
• Cyclizine
  • Injection (Canada)

If you are taking this medicine without a prescription, carefully read and follow any precautions on the label. For buclizine, cyclizine, and meclizine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to buclizine, cyclizine, or meclizine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—These medicines have not been shown to cause birth defects or other problems in humans. However, studies in animals have shown that buclizine, cyclizine, and meclizine given in doses many times the usual human dose cause birth defects, such as cleft palate.

Breast-feeding—Although these medicines may pass into breast milk, they have not been reported to cause problems in nursing babies. However, since these medicines tend to decrease the secretions of the body, it is possible that the flow of breast milk may be reduced in some patients.

Children—There is no specific information comparing use of buclizine, cyclizine, and meclizine in children with use in other age groups. However, children may be especially sensitive to the anticholinergic effects (e.g., dryness of mouth, nose, and throat) of these medicines.

Older adults—There is no specific information comparing use of buclizine, cyclizine, and meclizine in the elderly with use in other age groups. Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. However, older people may be especially sensitive to the anticholinergic effects (e.g., constipation; difficult urination; dryness of mouth, nose, and throat) of these medicines.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking buclizine, cyclizine, or meclizine, it is especially important that your health care professional know if you are taking the following:

• Central nervous system (CNS) depressants, other (medicines that make you drowsy or less alert) or
• Tricyclic antidepressants (medicine for depression)—Use with buclizine, cyclizine, or meclizine may increase the side effects of either medicine

Other medical problems—The presence of other medical problems may affect the use of buclizine, cyclizine, or meclizine. Make sure you tell your doctor if you have any other medical problems, especially:

• Asthma, bronchitis, emphysema, or other chronic lung disease—Cyclizine or meclizine may cause serious breathing problems in patients who have any of these conditions

• Enlarged prostate or
• Glaucoma or
• Intestinal blockage or
• Urinary tract blockage—Buclizine, cyclizine, or meclizine may make these conditions worse

• Heart failure—Cyclizine may make the condition worse

This medicine is used to relieve or prevent the symptoms of motion sickness or vertigo (dizziness caused by other medical problems). Take it only as directed. Do not take more of it or take it more often than stated on the label or ordered by your doctor. To do so may increase the chance of side effects.

Dosing—

The dose of buclizine, cyclizine, or meclizine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of buclizine, cyclizine, or meclizine. If your dose is different, do not change it unless your doctor tells you to do so.

For buclizine
• For oral dosage form (chewable tablets):
  • To prevent motion sickness:
    • Adults and teenagers—The usual dose is 50 milligrams (mg) thirty minutes before travel. The dose may be repeated every four to six hours if needed. Not more than 150 mg should be taken in one day.
    • Children—Dose must be determined by your doctor.

For cyclizine
• For oral dosage form (tablets):
  • To prevent and treat motion sickness:
    • Adults and teenagers—The usual dose is 50 milligrams (mg) thirty minutes before travel. The dose may be repeated every four to six hours if needed. Not more than 200 mg should be taken in one day.
    • Children 6 to 12 years of age—The usual dose is 25 mg thirty minutes before travel. The dose may be repeated every six to eight hours if needed. Not more than 75 mg should be taken in one day.
    • Children up to 6 years of age—Use and dose must be determined by your doctor.
• For injection dosage form:
  • To prevent and treat motion sickness:
    • Adults and teenagers—The usual dose is 50 mg injected into a muscle every four to six hours as needed.
    • Children—Dose is based on body weight and must be determined by your doctor. The usual dose is 1 mg per kilogram (0.45 mg per pound) of body weight injected into a muscle three times a day as needed.

For meclizine
• For oral dosage forms (tablets and chewable tablets):
  • To prevent and treat motion sickness:
    • Adults and children 12 years of age or older—The usual dose is 25 to 50 milligrams (mg) one hour before travel. The dose may be repeated every twenty-four hours as needed.
    • Children up to 12 years of age—Use and dose must be determined by your doctor.
  • To prevent and treat vertigo (dizziness):
    • Adults and children 12 years of age or older—The usual dose is 25 to 100 mg a day as needed, divided into smaller doses.
    • Children up to 12 years of age—Use and dose must be determined by your doctor.

Missed dose—

If you must take this medicine regularly and you miss a dose, take the missed dose as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store the tablets in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Tell the doctor in charge that you are taking this medicine before you have any skin tests for allergies. The results of the test may be affected by this medicine.

Buclizine, cyclizine, or meclizine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.

This medicine may cause some people to become drowsy or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.

Buclizine, cyclizine, and meclizine may cause dryness of the mouth. For temporary relief use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.

Along with its needed effects, a medicine may cause some unwanted effects. The following side effects may go away during treatment as your body adjusts to the medicine; however, check with your doctor if they continue or are bothersome:

• More common
  • Drowsiness 
  
  

• Less common or rare
  • Blurred or double vision;  constipation;  diarrhea;  difficult or painful urination;  dizziness;  dryness of mouth, nose, and throat;  fast heartbeat;  headache;  loss of appetite;  nervousness, restlessness, or trouble in sleeping;  skin rash;  upset stomach 
  
  

Not all of the side effects listed above have been reported for each of these medicines, but they have been reported for at least one of them. Buclizine, cyclizine, and meclizine are similar, so any of the above side effects may occur with any of these medicines.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, some of these medicines are used in certain patients to prevent the following medical conditions:

• Nausea and vomiting following surgery
• Nausea and vomiting following cancer radiation treatment

Other than the above information, there is no additional information relating to proper use, precautions, or side effects for these uses.