Dofetilide, Oral doh-FET-il-ide

What are other names for this medicine?

Type of medicine: antiarrhythmic (treats irregular heartbeat)

Generic and brand names: dofetilide, oral; Tikosyn

What is this medicine used for?

This medicine is taken by mouth to treat abnormal heart rhythms. It is used to restore normal heart rhythm, and also to maintain a regular, steady heartbeat.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• an allergic reaction to any medicine
• long QT syndrome (problems with electrical activity in the heart muscle) or if you have a close relative who has long QT syndrome
• hypokalemia (too little potassium) or hypomagnesemia (too little magnesium) in your blood
• liver or kidney problems

Tell your healthcare provider about any other prescription or nonprescription medicines, vitamins, or herbal products you are taking. This medicine can cause life-threatening side effects if you take it with certain other medicines.

Females of childbearing age: Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known whether this medicine will harm an unborn baby. Do not breast-feed while taking this medicine without your healthcare provider's approval.

How do I take it?

You will be given this medicine in a hospital by healthcare providers trained to give this medicine. Also, you will be monitored continuously by electrocardiograph (ECG). Your hospital stay usually lasts for 3 days or more. Then you will be given a prescription to take this medicine at home.

Read the Medication Guide that comes in the medicine package when you start your treatment and with every refill.

Take this medicine regularly as your healthcare provider prescribes. Do not take more or less or take it longer than prescribed. Taking too much of this medicine may cause side effects that could be fatal. Do not stop taking this medicine without your healthcare provider's approval, even if you feel better. Take your medicine at the same time each day to help you remember to take it. You may take this medicine with or without food.

What if I miss a dose?

Do not miss a dose. If you miss a dose, just take the next dose at the usual time. Never try to make up for a missed dose. You could increase the risk of a different type of abnormal heartbeat. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What if I overdose?

If you or anyone else has intentionally taken too much of this medicine, call 911 or go to the emergency room right away. If you pass out, have seizures, weakness or confusion, or have trouble breathing, call 911. If you think that you or anyone else may have taken too much of this medicine, call the poison control center. Do this even if there are no signs of discomfort or poisoning. The poison control center number is 800-222-1222.

Symptoms of an acute overdose may include: slow heartbeat, fainting, dizziness, weakness, confusion.

What should I watch out for?

Keep your appointments for tests. These tests will help your healthcare provider check if the amount you are taking is still right for you.

Do not take any medicines, including nonprescription products, without the approval of the healthcare provider who prescribed this medicine.

If you need emergency care, surgery, or dental work, tell the healthcare provider or dentist you are taking this medicine. If you need to be in the hospital, take this medicine with you. The hospital may not have this medicine. Do not run out of this medicine. Get your refills of this medicine on time. This medicine is only available through special pharmacies.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away). If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; chest pain or tightness in your chest; swelling of your lips, tongue, and throat).

Serious (report these to your healthcare provider right away): Rapid or irregular heartbeat, excessive or prolonged diarrhea (for more than 48 hours), sweating, vomiting, unusual thirst, loss of appetite, chest pain, shortness of breath, dizziness, lightheadedness.

Other: Headache, nausea, fever, chills, joint or muscle pain, trouble sleeping, rash, back pain, stomach pain.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• antibiotics such as azithromycin (Zithromax), clindamycin (Cleocin), erythromycin (Erythrocin, E.E.S., EryPed), clarithromycin (Biaxin, Prevpac), levofloxacin (Levaquin), ciprofloxacin (Cipro), moxifloxacin (Avelox), norfloxacin (Noroxin), trimethoprim (Trimpex, Proloprim), pentamidine, telithromycin (Ketek), and trimethoprim/sulfamethoxazole (Bactrim, Septra)
• antidepressants such as amitriptyline, desipramine (Norpramin), doxepin, imipramine (Tofranil), nortriptyline (Pamelor), trazodone, venlafaxine (Effexor, Effexor XR), fluoxetine (Prozac, Sarafem), fluvoxamine (Luvox), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), and escitalopram (Lexapro)
• antifungals such as fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), posaconazole (Noxafil), and voriconazole (Vfend)
• anti-HIV medicines such as abacavir (Ziagen), atazanavir (Reyataz), indinavir (Crixivan), darunavir (Prezista), fosamprenavir (Lexiva), lopinavir/ritonavir (Kaletra), nelfinavir mesylate (Viracept), ritonavir (Norvir), saquinavir (Invirase), and tipranavir (Aptivus)
• antipsychotic medicines such as chlorpromazine, fluphenazine, lithium (Lithobid), perphenazine, pimozide (Orap), prochlorperazine, quetiapine (Seroquel), risperidone (Risperdal), thioridazine, and ziprasidone (Geodon)
• breathing medicines such as albuterol (Proventil, Ventolin), salmeterol (Serevent, Advair), terbutaline (Brethine), and zafirlukast (Accolate)
• calcium channel blockers such as diltiazem (Cardizem), felodipine, isradipine (DynaCirc CR), nicardipine (Cardene), nifedipine (Adalat CC, Procardia), and verapamil (Calan, Covera-HS, Isoptin SR, Verelan, Tiazac)
• chloroquine (Aralen)
• cimetidine (Tagamet)
• diuretics such as amiloride, bumetanide, chlorothiazide (Diuril), chlorthalidone (Thalitone), ethacrynic acid (Edecrin), furosemide, hydrochlorothiazide (Microzide), indapamide (Lozol), metolazone (Zaroxolyn), torsemide (Demadex), triamterene (Dyrenium), and triamterene/hydrochlorothiazide (Dyazide, Maxzide)
• foscarnet (Foscavir)
• medicines to treat migraine headaches such as almotriptan (Axert), eletriptan (Relpax), frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt), sumatriptan (Imitrex), and zolmitriptan (Zomig)
• megestrol (Megace)
• metformin (Glucophage, Glucovance, Glucophage XR)
• nefazodone
• octreotide (Sandostatin, Sandostatin LAR)
• other medicines to regulate heartbeat such as amiodarone (Cordarone, Pacerone), disopyramide (Norpace, Norpace CR), flecainide (Tambocor), ibutilide (Corvert), procainamide, propafenone (Rythmol), and quinidine
• quinine

Do not eat grapefruit or drink grapefruit juice while taking this medicine. Grapefruit affects the way this medicine works and may increase the risk of side effects.

If you are not sure if your medicines might interact, ask your pharmacist or healthcare provider. Keep a list of all your medicines with you. List all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.