It is important that your doctor check your progress at regular visits to make sure the medicine is working properly. This will allow for changes to be made in the amount of medicine you are taking, if necessary.
This medicine can cause changes in your heart rhythm, such as conditions called PR, QRS, or QT prolongation. It may cause fainting or serious side effects in some patients. Contact your doctor right away if your symptoms do not improve or if they get worse.
Check with your doctor right away if you develop any of the following: chest pain; shortness of breath; swelling of your hands, ankles, or feet; or weight gain. These may be symptoms of heart failure.
This medicine can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests.
Propafenone 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.
If you have been using this medicine regularly for several weeks, do not suddenly stop using it. Check with your doctor for the best way to gradually reduce the amount you are taking before stopping completely.
This medicine may decrease the amount of sperm men make. Talk to your doctor if you have concerns about this.
Grapefruits and grapefruit juice may increase the effects of propafenone by increasing the amount of this medicine in your body. You should not eat grapefruit or drink grapefruit juice while you taking this medicine.
Tell your doctor if you are smoking tobacco.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.