Dofetilide

Dofetilide is a prescription medication used to treat adults with irregular heartbeat, known medically as atrial fibrillation or atrial flutter. Dofetilide belongs to a group of drugs called antiarrhythmic agents, which help restore regular heart rhythm.

This medication comes in capsule form and is usually taken twice a day, with or without food.

Some of the common side effects of dofetilide include headache, chest pain, and dizziness.

Dofetilide is a prescription medicine that is used to treat an irregular heartbeat (atrial fibrillation or atrial flutter).

It is not known if dofetilide is safe and effective in children under 18 years of age.

Dofetilide may be found in some form under the following brand names:

• Tikosyn

Dofetilide can cause serious side effects, including a type of abnormal heartbeat called Torsade de Pointes, which can lead to death. See "Drug Precautions".

The most common side effects of dofetilide include:

• headache
• chest pain
• dizziness

Call your doctor right away if you have signs of electrolyte imbalance:

• severe diarrhea
• unusual sweating
• vomiting
• not hungry (loss of appetite)
• increased thirst (drinking more than normal)

Tell your doctor if you have any side effects that bother you or do not go away.

These are not all the possible side effects of dofetilide. For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take medicines to treat:

• heart problems
• high blood pressure
• depression or other mental problems
• asthma
• allergies, or hay fever
• skin problems
• infections

Ask your doctor if you are not sure about the medicines you take. Tell your doctor about all prescription and non-prescription medicines, vitamins, dietary supplements, and any natural or herbal remedies. Dofetilide and other medicines may affect each other, causing serious side effects. If you take dofetilide with certain medicines, you will be more likely to have a different type of abnormal heartbeat.  See "Drug Precautions".

Dofetilide can cause serious side effects, including a type of abnormal heartbeat called Torsade de Pointes, which can lead to death.

To establish the right dose of dofetilide, treatment with dofetilide must be started in a hospital where your heart rate and kidney function will be checked for the first 3 days of treatment. It is important that when you go home, you take the exact dose of dofetilide that your doctor prescribed for you.

While you take dofetilide, always watch for signs of abnormal heartbeat.

Call your doctor and go to the hospital right away if you:

• feel faint
• become dizzy, or
• have a fast heartbeat

Do not take dofetilide if you:

• have an irregular heartbeat called long QT syndrome
• have kidney problems or are on kidney dialysis
• are allergic to dofetilide or any other ingredients in this medication
• take any of these medicines:
  • cimetidine (Tagamet)
  • verapamil (Calan, Verelan)
  • ketoconazole (Nizora, Xolegel, Extina)
  • trimethoprim alone (Proloprim, Trimpex) or the combination of trimethoprim and sulfamethoxazole (Bactrim, Septra)
  • prochlorperazine (Compazine, Compo)
  • megestrol (Megace)
  • hydrochlorothiazide alone or in combination with other medicines (Exidrix, Ezide, Hydrodiuril, Hydro-Par, Microzide, or Oretic)

Grapefruit and grapefruit juice may interact with dofetilide and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor.

Before taking dofetilide, tell your doctor about all of your medical conditions including if you:

• have heart problems
• have kidney or liver problems
• are pregnant or plan to become pregnant. It is not known if dofetilide will harm your unborn baby.
• are breastfeeding or plan to breastfeed. It is not known if dofetilide passes into your breast milk. You and your doctor should decide if you will take dofetilide or breastfeed. You should not do both.

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Dofetilide falls into category C. There are no well-controlled studies that have been done in pregnant women. Dofetilide should be used during pregnancy only if the possible benefit outweighs the possible risk to the unborn baby.

Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if dofetilide passes into your breast milk. You and your doctor should decide if you will take dofetilide or breastfeed. You should not do both.

• Take dofetilide exactly as your doctor tells you.
• Do not change your dofetilide dose unless your doctor tells you to.
• Your doctor will do tests before you start and while you take dofetilide.
• Do not stop taking dofetilide until your doctor tells you to stop. If you miss a dose, just take the next dose at your regular time. Do not take 2 doses of dofetilide at the same time.
• Dofetilide can be taken with or without food.

Take dofetilide exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The usual recommended dose range of dofetilide is 125 to 500 mcg once or twice daily. This dose will be based on your kidney and heart rhythm activity.

If you take too much dofetilide, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

If dofetilide is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention

• Store dofetilide between 59° to 86°F (15° to 30°C).
• Keep dofetilide away from moisture and humidity.
• Keep dofetilide in a tightly closed container.
• Keep dofetilide and all medicines out of the reach of children.

To minimize the risk of induced arrhythmia, patients initiated or re-initiated on dofetilide should be placed for a minimum of 3 days in a facility that can provide calculations of creatinine clearance, continuous electrocardiographic monitoring, and cardiac resuscitation. Dofetilide is available only to hospitals and prescribers who have received appropriate dofetilide dosing and treatment initiation education.