What is dofetilide?
Dofetilide is a heart rhythm medication, also called an antiarrhythmic.
Dofetilide is used to help keep the heart beating normally in people with certain heart
rhythm disorders of the atrium (the upper chambers of the heart that allow blood to flow into the
heart). Dofetilide is used in people with atrial fibrillation or atrial flutter.
Dofetilide may also be used for other purposes not listed in this medication guide.
What should I discuss with my healthcare provider before taking dofetilide?
You should not use this medication if you are allergic to dofetilide, or if you have
certain conditions. Be sure your doctor knows if you have:
There are certain drugs that should not be used
together with dofetilide.
Tell your doctor knows if you take any of the following
medications:
-
verapamil (Covera, Calan, Isoptin, Verelan);
-
cimetidine (Tagamet);
-
ketoconazole (Nizoral);
-
prochlorperazine (Compazine);
-
megestrol (Megace); or
-
trimethoprim (Proloprim, Trimpex, Bactrim, Cotrim,
Septra).
Before using dofetilide, tell your doctor if you are allergic to any
drugs, or if you have liver or kidney disease.
If you have any of these conditions, you may need a dose adjustment or special tests to
safely take dofetilide. Your doctor will tell you if any of your medication doses need to be
changed.
FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell
your doctor if you are pregnant or plan to become pregnant during treatment.
It is not known whether dofetilide passes into breast milk or if it could harm a
nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a
baby.
How should I take dofetilide?
Take dofetilide exactly as it was prescribed for you. Do not take the medication in larger
amounts or for longer than recommended by your doctor. Follow the directions on your
prescription label.
Dofetilide comes with patient instructions for safe and effective use. Follow these
directions carefully. Ask your doctor or pharmacist if you have any questions.
Dofetilide may be available only from a hospital or specialty pharmacy.
You may need to spend at least 3 days in a hospital setting when you
first start taking dofetilide.
This is so your heart rhythm and kidney function can be
monitored in case the medication causes serious side effects.
Your heart rate will be constantly monitored through electrocardiograph or ECG
(sometimes called an EKG). This machine measures electrical activity of the heart. This will
help your doctor determine the correct dofetilide dose for you.
Do not skip doses or stop taking dofetilide without first talking to your doctor.
Stopping suddenly may make your condition worse. You may need to use less and less before
you stop the medication completely.
Tell your doctor if you have an illness that involves diarrhea or vomiting lasting more
than a few hours. Prolonged diarrhea or vomiting can lower your potassium levels, making it
dangerous for you to use dofetilide.
To be sure this medication is helping your condition, your blood pressure will need to be
checked on a regular basis. Your kidney function will also need to be tested. Do not miss any
scheduled visits to your doctor.
Store dofetilide at room temperature away from moisture and heat. Keep the bottle
tightly closed when not in use.
What happens if I miss a dose of dofetilide?
Take the missed dose as soon as you remember. If it is almost time for your next dose,
wait until then to take the medicine and skip the missed dose.
Do not
take extra
medicine to make up the missed dose.
Where can I get more information about dofetilide?
Your pharmacist has information about dofetilide written for health professionals that you may read.
What are the possible side effects of dofetilide?
Get emergency medical help if you have any of these
signs of an allergic
reaction:
hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have a serious side effect such as:
-
fast or pounding heartbeat, chest pain, shortness of breath; or
-
feeling like you might pass out.
Less serious side effects may include:
-
headache or back pain;
-
dizziness;
-
nausea, diarrhea, stomach pain;
-
sleep problems (insomnia);
-
stuffy or runny nose, cough, sore throat; or
-
mild skin rash.
This is not a complete list of side effects and others may occur. Tell
your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.
What is the most important information I should know about dofetilide?
You should not use this medication if you have severe kidney disease or a history of
"Long QT syndrome."
There are many other medicines that can cause serious medical
problems if you take them together with dofetilide.
Tell your doctor about all the
prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal
products, and drugs prescribed by other doctors. Do not start using a new medication without
telling your doctor. Keep a list with you of all the medicines you use and show this list to any
doctor or other healthcare provider who treats you.
You may need to spend at least 3 days in a hospital setting when you
first start taking dofetilide.
This is so your heart rhythm and kidney function can be
monitored in case the medication causes serious side effects.
Tell your doctor if you have an illness that involves diarrhea or vomiting lasting more
than a few hours. Prolonged diarrhea or vomiting can lower your potassium levels, making it
dangerous for you to use dofetilide.
To be sure this medication is helping your condition, your blood pressure will need to be
checked on a regular basis. Your heart and kidney function will also need to be tested. Do not
miss any scheduled visits to your doctor.
Dofetilide may be available only from a hospital or specialty pharmacy.
What should I avoid while taking dofetilide?
Grapefruit and grapefruit juice may interact with dofetilide and lead to potentially
dangerous effects. Discuss the use of grapefruit products with your doctor. Do not increase or
decrease the amount of grapefruit products in your diet without first talking to your doctor.
What other drugs will affect dofetilide?
Many drugs can interact with dofetilide. Below is just a partial list. Tell your doctor if
you are using:
-
a diuretic (water pill);
-
HIV/AIDS medicine such as nelfinavir (Viracept) or
ritonavir (Norvir);
-
drugs that can affect heart rhythm, such as bepridil
(Vascor), cisapride (Propulsid), droperidol (Inapsine);
-
narcotic medication such as levomethadyl (Orlaam), or
methadone (Dolophine, Methadose);
-
antibiotics such as clarithromycin (Biaxin), erythromycin
(E-Mycin, E.E.S., Erythrocin, Ery-Tab), levofloxacin (Levaquin), moxifloxacin (Avelox), or
pentamidine (NebuPent, Pentam);
-
an antidepressant such as amitriptyline (Elavil, Etrafon),
desipramine (Norpramin), fluoxetine (Prozac), fluvoxamine (Luvox), imipramine (Janimine,
Tofranil), or paroxetine (Paxil);
-
medicines to treat psychiatric disorders, such as
chlorpromazine (Thorazine), haloperidol (Haldol), mesoridazine (Serentil), or thioridazine
(Mellaril); or
-
heart rhythm medicine such as amiodarone (Cordarone,
Pacerone), disopyramide (Norpace), ibutilide (Corvert), procainamide (Procan, Pronestyl),
quinidine (Quinidex, Quin-Release Quin-G), or sotalol (Betapace).
This list is not complete and there may be other drugs that can interact
with dofetilide. Tell your doctor about all the prescription and over-the-counter medications you
use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors.
Do not start using a new medication without telling your doctor. Keep a list with you of all the
medicines you use and show this list to any doctor or other healthcare provider who treats you.
What happens if I have an overdose of dofetilide?