Pacerone

Pacerone is a prescription medication used to treat adults with life-threatening abnormal heart rhythm known medically as ventricular arrhythmia. It is used when other medications fail to work. Pacerone belongs to a group of drugs called antiarrhythmic drugs. It affects the potassium level in the heart muscle which helps the heart resist irregular electrical signals.

This medication comes in tablet form and is taken once or twice daily.

Common side effects of Pacerone include nausea, vomiting, and tiredness.

Pacerone is a prescription medicine used in adults to treat life-threatening heartbeat problems called ventricular arrhythmias, for which other treatment did not work or was not tolerated. 

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

• Upsher-Smith Laboratories, Inc.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1‑800‑FDA-1088.

Pacerone can cause serious side effects that lead to death including lung damage, liver damage, worse heartbeat problems, and thyroid problems. See "Drug Precautions".

Some other serious side effects of Pacerone include:

• thyroid problems. Pacerone can cause thyroid problems, including low thyroid function or overactive thyroid function. Your doctor may arrange regular blood tests to check your thyroid function during treatment with Pacerone. Call your doctor if you have weakness, weight loss or weight gain, heat or cold intolerance, hair thinning, sweating, changes in your menses, swelling of your neck (goiter), nervousness, irritability, restlessness, decreased concentration, depression in the elderly, or tremor.
• skin problems. Pacerone can cause your skin to be more sensitive to the sun or to turn a bluish-gray color. In most patients, skin color slowly returns to normal after stopping Pacerone. In some patients, skin color does not return to normal.
• vision problems that may lead to permanent blindness. You should have regular eye exams before and during treatment with Pacerone. Call your doctor if you have blurred vision, see halos, or your eyes become sensitive to light.
• nerve problems. Pacerone can cause a feeling of “pins and needles” or numbness in the hands, legs, or feet, muscle weakness, uncontrolled movements, poor coordination, and trouble walking.

Other side effects of Pacerone include nausea, vomiting, constipation, and loss of appetite.

Call your doctor about any side effect that bothers you.

These are not all the side effects with one Pacerone. For more information, ask your doctor or pharmacist.

Tell your doctor about all the medicines you take including prescription and nonprescription medicines, vitamins and herbal supplements. Pacerone and certain other medicines can interact with each other causing serious side effects. Sometimes the dose of amiodarone or other medicines must be changed when they are used together. Especially, tell your doctor if you are taking:

• antibiotic medicines used to treat infections
• depression medicines
• blood thinner medicines
• HIV or AIDS medicines
• cimetidine (Tagamet), a medicine for stomach ulcers or indigestion
• loratadine (for example: Claritin, Alavert), a medicine for allergy symptoms
• seizure medicines
• diabetes medicines
• cyclosporine, an immunosuppressive medicine
• dextromethorphan, a cough medicine
• medicines for your heart, circulation, or blood pressure
• water pills (diuretics)
• high cholesterol or bile medicines
• narcotic pain medicines
• St. John's Wort

Know the medicines you take. Keep a list of them with you at all times and show it to your doctor and pharmacist each time you get a new medicine. Do not take any new medicines while you are taking amiodarone unless you have talked with your doctor.

Pacerone can cause serious side effects that can lead to death including:

• lung damage
• liver damage
• worse heartbeat problems
• thyroid problems

Call your doctor or get medical help right away if you have any symptoms such as the following:

• shortness of breath, wheezing, or any other trouble breathing; coughing, chest pain, or spitting up of blood
• nausea or vomiting; passing brown or dark-colored urine; feel more tired than usual; your skin and whites of your eyes get yellow; or have stomach pain
• heart pounding, skipping a beat, beating very fast or very slowly; feel light-headed or faint
• weakness, weight loss or weight gain, heat or cold intolerance, hair thinning, sweating, changes in your menses, swelling of your neck (goiter), nervousness, irritability, restlessness, decreased concentration, depression in the elderly, or tremor.

Because of these possible side effects, Pacerone should only be used in adults with life-threatening heartbeat problems called ventricular arrhythmias, for which other treatments did not work or were not tolerated.

Pacerone can cause other serious side effects. See "Side Effects". If you get serious side effects during treatment with Pacerone you may need to stop Pacerone, have your dose changed, or get medical treatment. Talk with your doctor before you stop taking Pacerone.

You may still have side effects after stopping Pacerone because the medicine stays in your body months after treatment is stopped.

Tell all your healthcare providers that you take or took Pacerone. This information is very important for other medical treatments or surgeries you may have.

Do not take Pacerone if you:

• have certain heart conditions (heart block, very slow heart rate, or slow heart rate with dizziness or lightheadedness)
• have an allergy to Pacerone, iodine, or any of the other ingredients in Pacerone.

Do not drink grapefruit juice during treatment with Pacerone. Grapefruit juice affects how Pacerone is absorbed in the stomach.

Tell your doctor about all of your medical conditions including if you:

• have lung or breathing problems
• have liver problems
• have or had thyroid problems
• have blood pressure problems
• are pregnant or planning to become pregnant. Pacerone can harm your unborn baby. Pacerone can stay in your body for months after treatment is stopped. Therefore, talk with your doctor before you plan to get pregnant.
• are breastfeeding. Pacerone passes into your milk and can harm your baby. You should not breast feed while taking Pacerone. Also, Pacerone can stay in your body for months after treatment is stopped.

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

Tell your doctor if you are pregnant or planning 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.

This medication falls into category D. Pacerone can harm your unborn baby. Pacerone can stay in your body for months after treatment is stopped. Therefore, talk with your doctor before you plan to get pregnant.

Tell your doctor if you are breastfeeding. Pacerone passes into your milk and can harm your baby. You should not breast feed while taking Pacerone. Also, Pacerone can stay in your body for months after treatment is stopped.

What to avoid while taking Pacerone:

• Do not drink grapefruit juice during treatment with Pacerone. Grapefruit juice affects how Pacerone is absorbed in the stomach.
• Avoid exposing your skin to the sun or sun lamps. Pacerone can cause a photosensitive reaction. Wear sun-block cream or protective clothing when out in the sun.
• Avoid pregnancy during treatment with Pacerone. Pacerone can harm your unborn baby.
• Do not breastfeed while taking Pacerone. Pacerone passes into your milk and can harm your baby.

Take Pacerone exactly as prescribed by your doctor.

The dose of Pacerone you take has been specially chosen for you by your doctor and may change during treatment. Keep taking your medicine until your doctor tells you to stop. Do not stop taking it because you feel better. Your condition may get worse. Talk with your doctor if you have side effects.

Your doctor will tell you to take your dose of Pacerone with or without meals. Make sure you take Pacerone the same way each time.

Do not drink grapefruit juice during treatment with Pacerone. Grapefruit juice affects how Pacerone is absorbed in the stomach.

Taking too many Pacerone can be dangerous. If you take too many Pacerone, call your doctor or go to the nearest hospital right away. You may need medical care right away.

If you miss a dose, do not take a double dose to make up for the dose you missed. Continue with your next regularly scheduled dose.

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

The dose your doctor recommends may be based on the following:

• the condition being treated
• other medical conditions you have
• other medications you are taking
• how you respond to this medication

The recommended starting dose of Pacerone (amiodarone) is 800 to 1,600 mg/day for 1 to 3 weeks.

When adequate arrhythmia control is achieved, or if you have side effects, the Pacerone (amiodarone) dose should be reduced to 600 to 800 mg/day for one month and then to the maintenance dose, usually 400 mg/day.

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

If Pacerone 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 Pacerone at room temperature. Protect from light. Keep amiodarone in a tightly closed container.
• Safely dispose of Pacerone that are out-of-date or no longer needed.
• Keep Pacerone and all medicines out of the reach of children.

This medication is intended for use only in patients with the indicated life-threatening arrhythmias because its use is accompanied by substantial toxicity.

Pacerone has several potentially fatal toxicities, the most important of which is pulmonary toxicity (hypersensitivity pneumonitis or interstitial/alveolar pneumonitis) that has resulted in clinically manifest disease at rates as high as 10 to 17% in some series of patients with ventricular arrhythmias given doses around 400 mg/day, and as abnormal diffusion capacity without symptoms in a much higher percentage of patients. Pulmonary toxicity has been fatal about 10% of the time. Liver injury is common with this medication, but is usually mild and evidenced only by abnormal liver enzymes. Overt liver disease can occur, however, and has been fatal in a few cases. Like other antiarrhythmics, Pacerone can exacerbate the arrhythmia, e.g., by making the arrhythmia less well tolerated or more difficult to reverse. This has occurred in 2 to 5% of patients in various series, and significant heart block or sinus bradycardia has been seen in 2 to 5%. All of these events should be manageable in the proper clinical setting in most cases. Although the frequency of such proarrhythmic events does not appear greater with Pacerone than with many other agents used in this population, the effects are prolonged when they occur.

Even in patients at high risk of arrhythmic death, in whom the toxicity of Pacerone is an acceptable risk, Pacerone poses major management problems that could be life-threatening in a population at risk of sudden death, so that every effort should be made to utilize alternative agents first.

The difficulty of using Paceronee effectively and safely itself poses a significant risk to patients. Patients with the indicated arrhythmias must be hospitalized while the loading dose of Pacerone is given, and a response generally requires at least one week, usually two or more. Because absorption and elimination are variable, maintenance-dose selection is difficult, and it is not unusual to require dosage decrease or discontinuation of treatment. In a retrospective survey of 192 patients with ventricular tachyarrhythmias, 84 required dose reduction and 18 required at least temporary discontinuation because of adverse effects, and several series have reported 15 to 20% overall frequencies of discontinuation due to adverse reactions. The time at which a previously controlled life-threatening arrhythmia will recur after discontinuation or dose adjustment is unpredictable, ranging from weeks to months. The patient is obviously at great risk during this time and may need prolonged hospitalization. Attempts to substitute other antiarrhythmic agents when Pacerone must be stopped will be made difficult by the gradually, but unpredictably, changing Pacerone body burden. A similar problem exists when Pacerone is not effective; it still poses the risk of an interaction with whatever subsequent treatment is tried.