In the U.S.—

• Antiarrhythmic

Moricizine ( mor-IH-siz-een) belongs to the group of medicines known as antiarrhythmics. It is used to correct irregular or rapid heartbeats to a normal rhythm by making the heart tissue less sensitive.

There is a chance that moricizine may cause new or make worse existing heart rhythm problems when it is used. Since other antiarrhythmic medicines have been shown to cause severe problems in some patients, moricizine is only used to treat serious heart rhythm problems. Discuss this possible effect with your doctor.

This medicine is available only with your doctor's prescription, in the following dosage form:

Oral
• Tablets (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For moricizine, the following should be considered:

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

Pregnancy—Moricizine has not been studied in pregnant women. However, this medicine has not been shown to cause birth defects or other problems in animal studies, although it affected weight gain in some animals. Before taking moricizine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding—Moricizine passes into the milk of some animals and may also pass into the milk of humans. However, this medicine has not been reported to cause problems in nursing babies.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of moricizine in children with use in other age groups.

Older adults—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 or if they cause different side effects or problems in older people. There is no specific information comparing use of moricizine in the elderly with use in other age groups, although the risk of some unwanted effects may be increased.

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. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

• Kidney disease or
• Liver disease—Effects may be increased because of slower removal of moricizine from the body

• Heart disease or
• Recent heart attack or
• If you have a pacemaker—Risk of irregular heartbeats may be increased

Take moricizine exactly as directed by your doctor, even though you may feel well. Do not take more or less of it than your doctor ordered.

This medicine works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses. Also, it is best to take each dose at evenly spaced times day and night. For example, if you are to take 3 doses a day, doses should be spaced about 8 hours apart. If you need help in planning the best times to take your medicine, check with your health care professional.

Dosing—

The dose of moricizine 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 moricizine. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine.

• For oral dosage form (tablets):
  • For irregular heartbeat (arrhythmias):
    • Adults—600 to 900 milligrams (mg) a day. This is divided into three doses and taken every eight hours.
    • Children—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of moricizine and remember within 4 hours, take it as soon as possible. However, if you do not remember until later, 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 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.

It is important that your doctor check your progress at regular visits to make sure the medicine is working properly. This will allow changes to be made in the amount of medicine you are taking, if necessary.

Your doctor may want you to carry a medical identification card or bracelet stating that you are using this medicine.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine.

Moricizine may cause some people to become dizzy or lightheaded. 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 dizzy.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• Less common
  • Chest pain;  fast or irregular heartbeat ;  shortness of breath;  swelling of feet or lower legs 
  
  

• Rare
  • Fever (sudden, high) 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Dizziness 
  
  

• Less common
  • Blurred vision;  diarrhea;  dryness of mouth;  headache;  nausea or vomiting;  nervousness;  numbness or tingling in arms or legs or around mouth;  pain in arms or legs;  stomach pain;  trouble in sleeping;  unusual tiredness or weakness 
  
  

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