Dofetilide

What is dofetilide?

Dofetilide is an antiarrhythmic medication. People take it when they have certain issues with their heart’s rhythm. It helps their heart return to a normal rhythm. Dofetilide (brand name Tikosyn®) is a capsule you swallow once or twice a day.

Your healthcare provider will calculate dofetilide dosing for you. Your dose may be different than someone else’s dose. A dose may be 125, 250 or 500 micrograms (mcg).

What is the drug dofetilide used for?

Dofetilide uses include treating and preventing:

• Atrial fibrillation (Afib, an irregular heart rhythm that starts in your heart’s upper chambers).
• Atrial flutter (another abnormal heart rhythm that begins in the upper chambers of your heart).

Healthcare providers also prescribe dofetilide for “off-label” uses. These are conditions that the medicine may help treat. But it wasn’t designed for them.

These dofetilide uses include other abnormal heart rhythms:

• Ventricular tachycardia (a fast heartbeat in your lower heart chambers).
• Supraventricular tachycardias (another type of fast heartbeat in your upper heart chambers — there are other kinds besides Afib and atrial flutter).
• Wolff-Parkinson-White syndrome (a fast heartbeat from an extra heartbeat signal path).

How do I start taking dofetilide?

You’ll spend three or four days in the hospital when you start taking dofetilide. This is to make sure the medication doesn’t cause any problems with your heart rhythm and to find the correct dose for you. Your healthcare provider may change the amount of medication you take while you’re in the hospital.

How do I take dofetilide at home?

Your prescription label tells you how much dofetilide to take and how often to take it.

Some things to remember:

• It’s important to take dofetilide exactly as prescribed.
• Take dofetilide at the same time every day.
• Keep taking your medicine even if you feel well.
• You can take dofetilide with or without food.
• Don’t skip a dose.
• Take only the amount of the medication that your provider prescribes.

If you have any questions about your prescription or how to get refills, ask your provider or pharmacist for help. Ask them to explain anything you don’t understand.

What should I tell my provider before taking dofetilide?

Before you get a prescription for dofetilide, tell your provider:

• If you’ve ever had an allergic reaction to dofetilide and what happened when you took it.
• The names of all prescription and over-the-counter (OTC) medications, vitamins and herbal supplements you take. Don’t start taking any new medications or supplements without asking your provider.
• If you have heart problems, especially a heart condition called long QT syndrome, or if you have kidney or liver problems, or low potassium or magnesium levels.
• If you’re pregnant, plan to get pregnant or are breastfeeding (chestfeeding).

What medicines prevent me from taking dofetilide?

Don’t take dofetilide (and tell your provider) if you take:

• Cimetidine (Tagamet® and Tagamet® HB).
• Cisapride.
• Dolutegravir (Tivicay® and Tivicay®PD).
• Verapamil (Calan®, Covera-HS® and Verelan®).
• Ketoconazole.
• Itraconazole (Sporanox®, Onmel® and Tolsura®).
• Trimethoprim (Proloprim® and Primsol®).
• Trimethoprim with sulfamethoxazole (Bactrim®, Septra® and Cotrimoxazole®).
• Hydrochlorothiazide (Microzide® and Oretic®).
• Ziprasidone.
• Amitriptyline or other tricyclic antidepressants.
• Promethazine.
• Prochlorperazine (Compro® and Procomp®).
• Quinidine.
• Disopyramide (Norpace® and Norpace® CR).
• Sotalol (Betapace® and Sorine®).

Which drugs can interact with dofetilide?

The following drugs can interact with dofetilide. Check with your provider before you take any of the following medications:

• Amiodarone (Cordarone® and Pacerone®).
• Digoxin (Lanoxin®, Lanoxicaps® and Digitek®).
• Metformin (Glucophage® and Riomet®).
• Megestrol.
• Diltiazem (Cardizem® and Diltzac®).
• Zafirlukast.
• Quinine.
• Fluconazole.
• Erythromycin (PCE® and Erythrocin®).
• Clarithromycin.
• Norfloxacin.
• Gatifloxacin.
• Moxifloxacin and other fluoroquinolone antibiotics.
• Fluoxetine.
• Sertraline.
• Paroxetine (Paxil® and Brisdelle®) and other selective serotonin reuptake inhibitors, or SSRIs.
• Furosemide.
• Triamterene.
• Amiloride and other diuretics.
• Indinavir and other protease inhibitors.

Like some of these drugs, grapefruit juice can increase the level of dofetilide in your body. Ask your provider if it’s safe for you to drink grapefruit juice while taking this medicine.

What should I do if I forget to take a dose?

Take the missed dose as soon as you remember. However, if you remember a missed dose near the time that you should take the next dose, take only the regularly scheduled dose. Don’t take a double dose. If you’re unsure of what to do, contact your provider or pharmacist.

What are the advantages of dofetilide?

Dofetilide can help you manage certain kinds of irregular heart rhythms. But it doesn’t cure them.

What are the side effects of dofetilide?

Dofetilide side effects may include:

• Chest pain.
• Headaches.
• Dizziness.
• Nausea.
• Diarrhea.
• Pain in your belly.

Although you take dofetilide to correct an irregular heartbeat, taking this medication can also increase your risk of developing another kind of irregular heartbeat. You may get Torsades de Pointes, a kind of ventricular tachycardia or fast heartbeat in your lower heart chambers.

This is why you have to start taking this medicine in the hospital. Healthcare providers need to monitor you and watch for this abnormal and potentially dangerous heartbeat.

How soon after treatment with dofetilide will I feel better?

It takes two to three hours for dofetilide to start working. Keep taking dofetilide even after you feel better.

How can I take care of myself when taking dofetilide?

Keep all of your provider and lab appointments to check your response to the medication. You’ll likely need an electrocardiogram (EKG) every six months to check your heart rate and rhythm. You may also need blood tests to see if you need any changes to your medication.

Read the information that comes with your prescription every time you get your prescription refilled, especially if you’ve had recent changes in your medications or health. If you have any questions, ask your pharmacist.

Other things you can do include:

• Telling the provider or dentist that you take dofetilide before you have any surgical or dental procedures, or emergency treatment.
• Wearing identification that says you’re taking dofetilide, which may be necessary.
• Never stopping this medicine without first asking your provider.
• Following your provider’s advice on diet, including guidelines for alcoholic beverages.
• Always having enough of this medication with you. Check your supply before vacations, holidays and other times when you may not be able to get a refill.

When should I see my healthcare provider?

Call your provider right away or seek emergency treatment if you have:

• Fast or irregular heartbeat.
• Pounding, slow heartbeat.
• Chest pain.
• Dizziness or lightheadedness.
• Difficulty breathing.
• Severe diarrhea.
• Vomiting with loss of appetite.
• Unusual sweating.
• Increased thirst.
• Rash.

Talk with your provider if you have these less serious side effects:

• Headache.
• Difficulty sleeping.
• Any other side effects that cause concern.

Where can I get my dofetilide prescription filled?

Contact your pharmacy to see if they can fill your prescription. Not all pharmacies carry dofetilide. If you have trouble finding the medication, talk to your provider.

How should I store dofetilide?

• Store dofetilide in a tightly closed container at room temperature in a dry place. Keep this medicine away from direct light and heat.
• Don’t store dofetilide in a bathroom or other damp areas. Moisture can break down the medication.
• Keep this and all other medications out of the reach of children.
• Never share your medication with anyone.
• Never take outdated medications. Some medication prescription labels list an expiration date. If your medication label doesn’t list an expiration date or if you’re unsure how old a medication is, call your pharmacy.

A note from Cleveland Clinic

Having an abnormal heart rhythm is unsettling. If your provider prescribes dofetilide, it may help you. Be sure to follow the instructions from your provider and on the prescription packaging. If you have any questions or concerns about this medication, ask your provider or pharmacist.