Procainamide affects the way your heart beats.

Procainamide is used to help keep the heart beating normally in people with certain heart rhythm disorders of the ventricles (the lower chambers of the heart that allow blood to flow out of the heart).

Procainamide may also be used for purposes not listed in this medication guide.

Procainamide is given in a hospital setting. Your heart rate, breathing, blood pressure and other vital signs will be watched closely while you are receiving procainamide.

You should not use this medication if you are allergic to procainamide, or if you have a serious heart condition such as "AV block" (unless you have a pacemaker), lupus, or a history of "Long QT syndrome."

If possible, before you receive procainamide, tell your doctor if you have congestive heart failure, circulation problems, a history of heart attack or stroke (including "mini-stroke"), a weak immune system, kidney or liver disease, myasthenia gravis, asthma, or if you are allergic to aspirin, sulfites, or any type of numbing medicine.

In an emergency situation it may not be possible before you are treated to tell your caregivers about your health conditions or if you are pregnant or breast feeding. Make sure any doctor caring for you afterward knows that you have received this medication.

Procainamide can lower blood cells that help your body fight infections. Tell your doctor if you develop signs of infection such as fever, chills, sore throat, flu symptoms, easy bruising or bleeding (nosebleeds, bleeding gums), loss of appetite, nausea and vomiting, sores in your mouth and throat, or unusual weakness.

You should not receive this medication if you are allergic to procainamide, or if you have:

• a serious heart condition such as "AV block" (unless you have a pacemaker);

• lupus; or

• a history of "Long QT syndrome."

If possible before you receive procainamide, tell your doctor if you have:

• congestive heart failure;

• circulation problems;

• a history of heart attack or stroke (including "mini-stroke");

• a weak immune system;

• kidney disease;

• liver disease;

• myasthenia gravis;

• asthma or sulfite allergy;

• if you are allergic to aspirin; or

• if you have ever had an allergic reaction to a numbing medicine.

FDA pregnancy category C. It is not known whether procainamide will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Procainamide can pass into breast milk and may harm a nursing baby. You should not breast-feed while you are using procainamide.

In an emergency situation, it may not be possible before you are treated with procainamide to tell your caregivers if you are pregnant or breast feeding. Make sure any doctor caring for your pregnancy or your baby knows you have received this medication.