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 "Drugs don't cure A-Fib but merely keep it at bay."¹⁶²

    The three main drug therapy treatment strategies are:
    1) to prevent blood clots and stroke by the use of blood thinners: (anticoagulants like warfarin, Coumadin, Jantoven; antiplatelets like Aspirin, Ecotrin, Plavix, Ticlid); or  Lovenox (an anticoagulant taken by injection), and Heparin (used in hospitalized patients. (Plavix and Ticlid are antiplatelet drugs like aspirin but they are not the same or interchangeable with aspirin. If your doctor prescribes Plavix or Ticlid, you should not substitute aspirin for them.)
     Blood thinners reduce but do not totally eliminate the risk of stroke. 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.
     It is often difficult to maintain this INR, especially when you first start on warfarin. You may have to take sometimes weekly PT tests in your doctor's office till you get the warfarin dosage and INR right. There are home use kits available for testing your own INR (for example, see http://www.PTINR.com}.
    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.
    (If you can't or don't want to take blood thinners, an option is to have a device installed to  close off the Left Atrial Appendage where 90-95% of A-fib strokes come from (Watchman, Amplatzer currently in clinical trials). Installing the Watchman device, for example, is a low risk procedure that takes only a short time. Then you would usually not need to be on blood thinners. For a partial list of doctors installing the Watchman device, see Doctors Installing the Watchman Device.)
    (Added 4/12/2011): Removing or closing off the Left Atrial Appendage (LAA) may affect how well the heart pumps and is of special concern to athletes and to those with heart pumping problems. In canine studies the LAA provided 17.2% of the whole left atrial volume of blood pumped.²⁵⁷ It's possible that removing or closing off the LAA may lead to heart pumping problems. The LAA is like a surge tank on a hot water heater. When the Mitral Valve closes, the LAA absorbs the surge of blood. When the LAA is amputated or closed off, this may cause increased pressure in the Pulmonary Veins and exercise intolerance. Few, if any, centers currently perform pre- and post-amputation exercise testing.)
    (Added 4/7/11) The FDA has approved a noose-like device that completely closes off the Left Atrial Appendage which dies and is no longer electrically active. See Lariat II.
    (Added 11/30/10:) The FDA recently approved a new blood thinner called dabigatran (brand name Pradaxa) which is as effective or even more effective than warfarin without many of the accompanying problems of warfarin. It will probably replace warfarin as the blood thinner of choice for A-Fib. See Dabigatran to Replace Warfarin and Dabigatran Now Available in Pharmacies.
    Dabigatran (brand name Pradaxa) is a direct thrombin inhibitor, a newer type of medication. Thrombin is an enzyme that converts soluble fibrinogen into insoluble fibrin. Fibrin is a fibrous protein involved in the clotting of blood. It forms a mesh or clot over a wound.  

    2)  Another drug strategy is to try to control the heart rate (ventricular beats), but leave the heart in A-Fib by what are called "rate control" drugs.¹⁰⁹ Rate control drugs aren't really a "treatment" for A-Fib. Though they slow the rate of the ventricles, they leave you in A-Fib. They may alleviate some A-Fib symptoms, but do not address the primary risks of stroke and death associated with A-Fib.²³⁵  Leaving patients in A-Fib overworks the heart and leads to remodeling and fibrosis which increase the risk of stroke.²⁶⁴ See Fibrosis Predicts Stroke Risk. Mellanie True-Hills of StopAfib.org asks, “Should we leave folks in A-Fib long term, especially the non-elderly? Between the risk of heart failure, and fibrosis from long-term remodeling increasing stroke risk, could staying in A-Fib long-term be a death sentence?”²⁶³ If your doctor only prescribes rate control meds for your A-Fib, you should question him/her and probably get a second opinion.        

    3) another drug treatment strategy is to try 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 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 slowly and constipation.⁶²
    Calcium-channel blockers include: diltiazem (Cardizem, Tilazem, Cartia XT)  [the generic name of a medication is listed first, the Brand name is in parentheses] and verapamil (Calan, Isoptin). 
 
    2. 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 slowly, tiredness, and loss of sex-drive.^{62, 275} In many people, beta-blockers can reduce heart rate by 10 to 30 beats per minute.²⁸¹    
    Beta-blockers include: atenolol (Tenormin), metoprolol (Lopressor, Toprol-XL), esmolol HCI (Brevibloc), propranolol (Inderal), timolol, nadolol, and pindolol and the newer drugs carvedilol (Coreg) and nebivolol (Bystolic).
    (A new study casts doubt on the effectiveness of most beta-blockers, because they promote fibrosis in the heart. Here is the actual medical language: Beta-blockers "undermine the structure and function of the heart...Blocking the beta-receptor alone promotes cardiac remodeling via growth of cardiac fibroblasts induced by alpha-adrenergic receptor signaling. The growth of fibroblasts in the heart further damages the integrity and function of the heart."²⁴⁷ 
    Carvedilol, however, targets both the beta- and alpha-adrenergic receptors on the heart muscle. "Beta-blockers (like carvedilol) which target both receptors "offer the most benefit to cardiac patients." A study in 2003 showed that carvedilol produced a greater survival rate than metoprolol.²⁴⁷ [Thanks to Janet Brown for calling our attention to this research.]
    Nebivolol seems to eliminate most of the common bad side effects of beta blockers by dilating blood vessels through the release of nitric oxide. But it also only blocks Beta 1 receptors. See nebivolol.)

    3. Cardiac Glycosides slow down and control the heart rate by blocking the electrical conduction between the atria and ventricles. The most widely prescribed Glycoside is digoxin (a Digitalis compound, brand names Lanoxin, Digitek), but medical authorities consider it the least effective.⁶ Digoxin is the most commonly used drug for rate control; but it is only effective at controlling heart rate at rest, when for example you are in the doctor's office.  But when you leave, your heart rate may go too high.²⁷⁴ Beta-blockers and calcium-channel blockers are generally more effective than Digoxin.²⁷⁴

    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 blood thinners.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 Up-to 50% of patients experience a recurrence of A-Fib after 1-year of antiarrhythmic treatment, and up-to 85% experience a recurrence after 2-years.¹⁵⁹ 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). 
    According to Drs. Savelieva and Camm, "The plethora of antiarrhythmic drugs currently available for the treatment of A-Fib is a reflection that none is wholly satisfactory, each having limited efficacy combined with poor safety and tolerability."²⁴⁴

Types of antiarrhythmic drugs
    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). Only approved in the US for ventricular arrhythmias. (Class II and class III drug---a beta-blocker with antiarrhythmic effects). Should not be used in patients with severe heart failure or those with a long QT interval (see EKG Signal), because it may trigger a lethal cardiac arrhythmia in those patients. May cause severe fatigue.²⁵²
     Dofetilide (Tikosyn): FDA-approved for conversion and maintenance. (Class III drug). Patients starting this medication must be monitored in a hospital for three days.
    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, thyroid, and liver. (Class III drug but it also blocks Sodium Channels like a Class I drug.)
    Dronedarone (Multaq): FDA approved in 2009. Chemically similar to amiodarone. While not as effective as amiodarone, it has less toxic side effects. See Dronedarone Safe in ATHENA Clinical Trials. Not for patients with severe heart failure.
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

Xanax (alprazolam)  
    Sally writes that her A-Fib comes on at night and is very severe, preventing her form sleeping. "I get up and take Xanax .05 mg, and within 15 minutes or so, the A-Fib stops. And I can go to sleep." Xanax does seem to have beta-blocker properties, though it is primarily used to help panic attacks. See Xanax story. But be advised that Xanax is a controlled substance and might be addictive. (The author isn't aware of this use of Xanax for A-Fib and welcomes comments on this subject.)


"PILL-IN-THE-POCKET" TREATMENT
    Another treatment approach for A-Fib is to take 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)
    Another person writes she would take Rythmol 300 mg and Inderal 20 mg, wait three hours, then take Inderal 20 mg, wait three hours, then again start the Rythmol 300 mg and Inderal 20 mg, etc. Although she daily took a 325 mg coated aspirin, during a bout of A-Fib she would also chew an 81 mg baby aspirin. (Marilyn, E-mail: nmshook (at) sbcglobal.net)
    (Leon and Marilyn were both later cured of A-Fib by Pulmonary Vein Ablations. You can read their stories at: TWO DIFFERENT "PILL-IN-THE-POCKET" APPROACHES---BOTH TURN TO CATHETER ABLATION FOR A CURE)
    Another treatment strategy is to take lower doses of an antiarrhythmic med on a regular basis, then take a higher dose during an A-Fib attack. Reg writes he takes 300 mg of flecainide, and 2 hours later goes back into SR. He normally is on a loading dose of flecainide 100 mg in the morning and 50 mg in the afternoon. (Email: r.j.tooth (at) shu.ac.uk. The "@" is written as "at" to prevent access by automated spam lists.)
    Will writes that he takes Rhythmol SR 325 regularly. If he gets a break-through event of A-Fib, he takes 600 propafenone, immediate release. "This always gets me back in Sinus Rhythm, usually in 90 minutes."
    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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