Dofetilide (patient information)

# IMPORTANT WARNING
Tikosyn can cause your heart to beat irregularly. You will need to be in a hospital or another place where you can be monitored closely by your doctor for at least 3 days when you are started or restarted on dofetilide. It is important to read the patient information provided to you every time you begin therapy with dofetilide.

# Why this medication is prescribed
Dofetilide is used to treat irregular heartbeats. It improves your heart rhythm by relaxing an overactive heart.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

# How this medication should be used
Dofetilide comes as a capsule to take by mouth. It is usually taken twice a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take dofetilide exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Do not take a double dose.
Dofetilide controls abnormal heart rhythms but does not cure them. Continue to take dofetilide even if you feel well. Do not stop taking dofetilide without talking to your doctor.

# Special Precautions
Before taking dofetilide:
- tell your doctor and pharmacist if you are allergic to dofetilide or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially antipsychotics, bepridil (Vascor), cimetidine (Tagamet), cisapride (Propulsid), clarithromycin (Biaxin), diltiazem (Cardizem), diuretics ('water pills'), erythromycin (E.E.S., E-Mycin, others), HIV protease inhibitors such as ritonavir (Norvir), itraconazole (Sporanox), ketoconazole (Nizoral), medications for dizziness or nausea, medications for depression such as amitriptyline (Elavil) or fluoxetine (Prozac), megestrol (Megace), metformin (Glucophage), other medications for irregular heart beats such as amiodarone (Cordarone), norfloxacin (Noroxin), prochlorperazine (Compazine), quinine (Formula Q), trimethoprim (Proloprim, Trimpex), trimethoprim and sulfamethoxazole (Bactrim, Septra), verapamil (Calan, Covera, Verelan), zafirlukast (Accolate), and vitamins.
tell your doctor if you have or have ever had long QT syndrome (a type of heart problem), or kidney or liver disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking dofetilide, call your doctor.

# Special dietary instructions
Talk to your doctor before drinking grapefruit juice. It may be best to drink other fruit juices while taking dofetilide.

# What to do if you forget a dose
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

# Side Effects

## Minor Side Effects
Dofetilide may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- headache
- chest pain
- dizziness
- respiratory infection
- flu-like symptoms
- stomach pain
- back pain
- diarrhea
- difficulty sleeping

## Severe Side Effects
If you experience any of the following symptoms, call your doctor immediately:
- irregular heartbeat
- rash
- sweating
- upset stomach
- vomiting
- loss of appetite or thirst
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online  or by phone .

# Storage conditions needed for this medication
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

# In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

# Other information
Keep all appointments with your doctor and the laboratory. Your heart rhythm should be checked regularly to determine your response to dofetilide. Your doctor will also want to follow your kidney function and blood level of potassium closely while you are taking dofetilide.
If you are ill for more than 24 hours with diarrhea, vomiting, or sweating and have not been able to take in much fluid or nutrition you should call your doctor before taking your next dose of dofetilide.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

# Brand names
- Tikosyn