Atrial Fibrillation
 RESOURCES FOR PATIENTS

MEDICATIONS
     You go to your doctor and he prescribes a medication you've never heard of, that sounds like something from Star Wars. When you have A-Fib, the strange medication names and medical jargon can be confusing and somewhat overwhelming. The purpose of this section is to describe in everyday language the various medications for A-Fib---how they work, how they might affect you.  Hopefully this will give you a basic understanding of the various medications you may be prescribed, so that you can become an intelligent participant in your own healing process.

    In general, don't expect miracles from current medications. To date, the magic pill that will cure your A-Fib probably doesn't exist.⁵

    The three main drug therapy treatment strategies are:
    1) to prevent blood clots and stroke by the use of blood thinners like warfarin (Coumadin, Jantoven), Lovenox (an anticoagulant taken by injection), Heparin (used in hospitalized patients), and aspirin (Ecotrin, Plavix, Ticlid). Blood thinners reduce but do not totally eliminate the risk of stroke.³⁶ To be effective warfarin must be maintained at a certain level in the blood stream (INR---International Normalized Ratio between 2.0 and 3.0). Above 4.0 you run the risk of having a hemorrhagic (bleeding) stroke. Below 2.0 you are more in danger of having an ischemic (clotting) stroke, the kind that most often occurs in A-Fib.
    In general, aspirin is less effective than warfarin.⁴⁵ (See FAQs question #10 Which is Better---Warfarin or Aspirin?).
    You should also get tested for variations in the CYP2C9 and VKORC1 genes which influence how you respond to warfarin (Coumadin). If your doctor doesn't provide this testing, you may want to think about getting a second opinion. These tests could save you heart problems related to over- and under-dosing of warfarin.
    2)  to control the heart rate (ventricular beats), but leave the heart in A-Fib by what are called "rate control" drugs.¹⁰⁹
    3) to stop the A-Fib and make your heart beat normally by what are called "antiarrhythmic" drugs.

        RATE CONTROL MEDICATIONS
    Medications used for rate control can be categorized as:
    1.  Calcium-channel blockers such as diltiazem (Cardizem, Tilazem, Cartia XT)  [the generic name of a medication is listed first, the Brand name is in parentheses] and verapamil (Calan, Isoptin). Calcium-channel blockers prevent or slow the flow of calcium ions into smooth muscle cells such as the heart and blood vessels. Calcium-blockers are preferred if you have heart or lung disease. Common side effects are the heart beats too slow and constipation.⁶²
    2. Beta-blockers such as atenolol (Tenormin), metoprolol (Lopressor, Toprol-XL), esmolol HCI (Brevibloc)  propranolol (Inderal), timolol, and pindolol. Beta-blockers "block" the action of adrenaline on beta receptors in the cells of heart muscle. They slow down conduction through the heart and make the AV Node less sensitive to A-Fib impulses. Beta-blockers are better for active or young people, because exercise reduces the effectiveness of Digitalis and Calcium-channel blockers. Common side effects are: the heart beats too slow, tiredness, and loss of sex-drive.⁶²
    3. Digoxin (a Digitalis compound, brand namesLanoxin, Digitek). Digoxin slows down and controls the heart rate by blocking the electrical conduction between the atria and ventricles. Digoxin is probably the most widely prescribed drug for rate control, but medical authorities consider it the least effective.⁶

    If you are using any of the above rate control drugs, please be advised that you will still have A-Fib. Only your lower heart (the ventricles) is controlled. You are still at risk of stroke and must continue taking anticoagulants.⁷

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        "ANTIARRHYTHMIC" MEDICATIONS
   In general current "antiarrhythmic" (anti irregular heart rhythm) drugs aren't always effective and tend to have bad side effects such as pulmonary fibrosis and impaired liver function.^8,9,10,55  They also become less effective over time, with approximately half of the patients eventually developing resistance to them.⁵⁵ Many antiarrhythmic drugs require you to be hospitalized for 3-4 days when they are initially administered, in order to monitor you for bad side effects. Some antiarrhythmic meds can have a "pro-arrhythmic" effect on some people (people react differently to medications). 
    Antiarrhythmic drugs are grouped in "classes" according to how they work.
    1. Class I are Sodium Channel Blockers which decrease the speed of electrical conduction in the heart muscle.
    2. Class II are Beta-Adrenergic or Beta-Blockers which slow down conduction through the heart and make the AV node less sensitive to A-Fib impulses.
    3. Class III are Potassium Channel Blockers which slow nerve impulses in the heart.
    4. Class IV are Calcium Channel Blockers which prevent or slow the flow of calcium ions into smooth muscle cells such as the heart. This impedes muscle cell contraction, thereby allowing blood vessels to expand and carry more blood and oxygen to tissues.

    Here is a list of the more commonly used antiarrhythmic drugs, based on an article by Dr. R. Falk of the Boston University School of Medicine:¹¹
      Procainamide (Procan SR, Promine, Pronestyl, Procanbid): Slows nerve impulses in the heart and reduces the sensitivity of heart tissue. Not FDA approved for A-Fib. Long-term use associated with lupus. Generally not used as a first-time drug because of bad side effects. Less effective against A-Fib than the other Class 1A drugs Quinidine and Disopyramide.²⁴ (Class 1A drug)
    Quinidine (Quinaglute, Quinidine Glaconate, Quinidex): FDA approved for A-Fib but risk of death increases during long-term use. Generally not used as a first-time drug because of bad side effects such as increasing the heart rate and impairing the heart's pumping efficiency. (Class 1A drug)
    Disopyramide (Norpace): Not FDA approved for A-Fib. Strong negative inotropic effect (heart muscle contractions weakened). Generally not used as a first-time drug. Good for patients with nocturnal or post-prandial (after meals) A-Fib.²⁷ (Class 1A drug)
    Flecainide (Tambocor): Slows nerve impulses in the heart and makes the heart tissue less sensitive. Approved only for paroxysmal (occasional) A-Fib with structurally normal heart. Normally the first drug tried on otherwise healthy patients with new A-Fib. Not recommended after a heart attack or if you have a structural heart disease. (Class 1C drug)
    Propafenone (Rhythmol and the newer version Rhythmol SR) : Same limitations as flecainide. (Class 1C drug)
    Sotalol (Betapace):  Not recommended (conversion from A-Fib to normal rhythm rate is low). (Class II and class III drug)
     Dofetilide (Tikosyn): FDA-approved for conversion and maintenance. (Class III drug)
    Amiodarone (Cordarone, Pacerone): Not FDA-approved for A-Fib. Moderately effective for conversion from A-Fib to normal rhythm, but onset is slow. Good rate slowing in A-Fib. This is usually the last drug tried on patients because of its toxic side effects particularly in the lungs, liver and thyroid. (Class III drug but it also blocks Sodium Channels like a Class I drug.)
    Ibutilide (Corvert): Not for patients with low blood potassium, a prolonged QT interval (slow heart beat), or torsade de pointes (very irregular, fast ventricular heart beats). Effective in electrical cardioversion. Often used in place of Electrocardioversion (33% to 49% success rate) and is generally more effective in cases of Atrial Flutter than in A-Fib.¹⁰⁸ (Class III drug)

    The Class 1 drugs Quinidine, Procainamide, Disopyramide, Flecainide, and Propafenone should probably be avoided if you've had a heart attack or have structural heart disease. The Class III drugs Amiodarone, Sotatol, Dofetilide, and Azimilide appear to be safer to use if you have structural heart disease.¹² In structurally normal hearts, Class IC drugs (Flecainide and Propafenone) cause less heart rhythm problems and are the least toxic.¹³

"PILL-IN-THE-POCKET" TREATMENT
    Another treatment approach for A-Fib is to take a stronger dose of an antiarrhythmic med at the time of an A-Fib attack. For example, one person writes that he takes 100 mg of flecainide three times at intervals of twenty minutes when he has an A-Fib attack. This often shortens the time of an A-Fib attack. "It (the Pill-In-The-Pocket treatment) has changed my life in that it reduces my time in A-Fib to usually a couple of hours as opposed to between 12 to 36 hours. It allows me to recover completely in a lot quicker time, because my heart hasn't been going crazy for a day or more. And it also allows me to remain out of hospital, which has been fantastic." ( Leon, E-mail: sandman_oz (at) yahoo.com)
    Some people take lower doses of an antiarrhythmic med on a regular basis, then take a higher dose during an A-Fib attack. Others use the antiarrhythmic drug only during an A-Fib attack.
    At best, the Pill-In-The-Pocket treatment is a stop gap measure rather than a "cure" of A-Fib.  (See also in the FAQs section "Is the "Pill-In-The-Pocket" treatment a cure for A-Fib? When should it be used?")

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