Tikosyn (dofetilide) is a brand-name oral capsule that’s prescribed for atrial fibrillation and atrial flutter in adults. As with other drugs, Tikosyn can cause side effects, such as headache, dizziness, and chest pain.

Tikosyn has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effect specifics” section.

Tikosyn can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Tikosyn in clinical trials:

  • headache
  • dizziness
  • insomnia (trouble sleeping)
  • nausea
  • chest pain (see “Side effect specifics” below)

Mild side effects can occur with Tikosyn use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Tikosyn’s prescribing information.

Mild side effects that have been reported with Tikosyn include:

  • headache
  • dizziness
  • insomnia (trouble sleeping)
  • nausea
  • diarrhea
  • skin rash
  • trouble breathing
  • abdominal pain
  • respiratory infection, such as the common cold
  • chest pain (see “Side effect specifics” below)

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Tikosyn and want to tell the FDA about it, visit MedWatch.

Tikosyn may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Tikosyn’s prescribing information.

If you develop serious side effects while taking Tikosyn, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

  • liver damage, which may include symptoms such as:
  • stroke, which may include symptoms such as:
    • headache
    • difficulty speaking or understanding
    • numbness or paralysis, especially on one side of the body
    • vision problems in one or both eyes
  • heart attack, which may include symptoms such as:
    • feeling of pressure, squeezing, pain, or tightness in your chest
    • shortness of breath
    • feeling dizzy or lightheaded
    • sweating
  • paralysis of parts of your body or face
  • risk of new or worsening arrhythmia (see “Side effect specifics” below)
ALLERGIC REACTION

For some people, Tikosyn capsules can cause an allergic reaction.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Tikosyn, your doctor may recommend taking a different medication instead.

Tikosyn may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Does Tikosyn cause long-term side effects?

It’s possible. Long-term side effects refer to side effects that can start at any time during treatment or side effects that don’t go away even after you stop taking the drug.

Long-term side effects aren’t common but may include heart attack or arrhythmia. These side effects may require additional treatments that you will need to take long-term.

In addition, liver damage caused by Tikosyn may not go away even after treatment is stopped.

If you have concerns about possible long-term side effects with Tikosyn, talk with your doctor or pharmacist.

Will I experience side effects if I stop taking Tikosyn?

No, you will not likely experience side effects if you stop taking Tikosyn. However, you shouldn’t stop taking Tikosyn without first talking with your doctor.

Tikosyn treats certain heart rhythm problems, including atrial fibrillation and atrial flutter. It’s possible that when you stop taking the drug, your heart rhythm problems could come back.

Talk with your doctor if you have questions about stopping treatment with Tikosyn.

Does Tikosyn cause weight gain or high blood pressure?

No, weight gain or high blood pressure weren’t reported as side effects in Tikosyn’s clinical trials.

Although it isn’t common, Tikosyn can cause edema in some people. Edema is a buildup of fluid and swelling that commonly affects hands, arms, legs, or feet. Edema could lead to temporary weight gain, but this weight gain should go away when the edema is treated.

Talk with your doctor or pharmacist if you have questions or concerns about weight gain or high blood pressure while taking Tikosyn.

Learn more about some of the side effects that Tikosyn may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Tikosyn.

Risk of new or worsening arrhythmia

Tikosyn has a boxed warning about the risk of new or worsening arrhythmia. (An arrhythmia is an irregular heartbeat). A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

Treatment with Tikosyn may cause a type of serious arrhythmia called Torsades de pointes, which can be life threatening. Other arrhythmias, including ventricular tachycardia or ventricular fibrillation, may also occur during treatment with Tikosyn. Arrhythmias were a common side effect in Tikosyn’s clinical trials.

Symptoms of an arrhythmia may include:

  • dizziness or lightheadedness
  • heart palpitations
  • shortness of breath
  • chest pain
  • nausea and vomiting
  • loss of consciousness

You may be at a higher risk of arrhythmias if you have heart disease, kidney disease, such as chronic kidney disease, or have an existing arrhythmia called long QT syndrome.

Taking a higher dose of Tikosyn may also increase your risk of arrhythmias.

What you can do

Because the risk for arrhythmia is higher when first starting treatment with Tikosyn, you must stay in a hospital or clinic for the first 3 days of taking the drug. This is so your doctor can monitor your heart rhythm and adjust your dose to make sure it is right for you. They can also treat you quickly if you develop an arrhythmia.

While you are taking Tikosyn, your doctor will continue to check your heart rhythm and blood tests to monitor how well your heart and kidneys are working. If they notice any signs of kidney problems or changes in your heart rhythm, they may adjust your dose of Tikosyn or recommend that you stop taking the drug.

Chest pain

Tikosyn can cause chest pain in some people. This was a common side effect reported in Tikosyn’s clinical trials. Chest pain is typically mild and will go away on its own.

However, chest pain can also be a sign of a more serious problem, such as a heart attack. Symptoms of a heart attack may include:

  • chest pain that spreads to your jaw, arm, or back
  • trouble breathing
  • sweating
  • weakness

What you can do

It’s a good idea to talk with your doctor if you experience a side effect of chest pain, even if it is mild.

If you experience symptoms of a heart attack or feel your symptoms are life threatening, call 911 or your local emergency number.

Below is important information you should consider before taking Tikosyn.

Tikosyn has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effect specifics” section.

Other precautions

Before taking Tikosyn, discuss your health history with your doctor. Tikosyn may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.