Drug (Class) |
Indication |
Dose/Administration Therapeutic Level/Half-Life |
Side Effects |
Comments |
Adenosine (Adenocard) |
First-line therapy to terminate AV nodal active SVT (AVNRT, CMT)Can be diagnostic in AV nodal passive rhythms by causing AV block and revealing underlying atrial mechanism, and in wide complex tachycardias of uncertain originVT arising in the RVOT that is due to after depolarizations may respond to adenosine |
6 mg given very rapidly IV followed by rapid saline flushMay follow with 12 mg if needed and repeat 12 mg if no effectHalf-life = 9 seconds |
Acute onset of AV block usually lasting a few seconds. May result in brief period of asystole or bradycardia that is not responsive to atropineTorsades can occur in patients who are susceptible to bradycardia-dependent arrhythmiasFlushing, hot flash, acute dyspnea lasting a few seconds, chest pressureCan precipitate bronchoconstriction in asthmatic patients |
Very short half-life so side effects are transientWarn patients about side effects before giving drug—especially dyspnea. It may be helpful to have patient take a deep breath while injecting drug to ↓ dyspneic sensationShould not be used when arrhythmia is known to be atrial fib or flutterMonitor ECG during administration and be prepared for cardioversionMay accelerate accessory pathway conduction and should not be used when antegrade conduction is occurring over accessory pathwayMay rarely accelerate ventricular rate in atrial flutterDrug interactions: Theophylline (and related drugs) and caffeine antagonize effects of adenosine and make it ineffectiveDipyridamole and carbamazepine potentiate effects of adenosine |
Amiodarone (Cordarone)(Classified as a class III antiarrhythmic but has powerful class I sodium channel blocking effects, moderate class II β-blocking effects, and weak class IV calcium channel blocking effects) |
Life-threatening ventricular arrhythmias: recurrent VF, recurrent hemodynamically unstable VTAlso widely used for:Conversion of atrial fib to sinus rhythm and maintenance of NSRSlowing conduction through accessory pathways in atrial fib or CMT |
PO: 800-1,600 mg q.d. for 1-3 weeks, then 400-800 mg q.d. for 1-3 weeksMaintenance: 100-400 mg/dayMay be given as single daily dose or bid if GI intolerance occursIV: 1,000 mg over first 24 hours given as follows:First rapid infusion: 150 mg over first 10 minutes (15 mg/min)(Add 3 mL [150 mg] to 100 mL D5W) Infuse 100 mL over 10 minutesFollowed by slow infusion: 360 mg over next 6 hours (1 mg/min) (Add 18 mL [900 mg] to 500 mL D5W) Infuse at 33.6 mL/hMaintenance infusion: 540 mg over next 18 hours (0.5 mg/min)(Decrease rate of slow loading infusion to 0.5 mg/min) Infuse at 16.8 mL/hMay continue with 0.5 mg/min for 2-3 weeks if needed. Central line recommended for long-term infusionsIf breakthrough VT occurs, may give supplemental doses of 150 mg over 10 min. (150 mg added to 100 mL D5W) |
Bradycardia, heart blockProarrhythmia (VF, incessant VT, torsades)Hypotension with IV formPulmonary fibrosis, corneal microdeposits, photosensitivity, blue skin, thyroid dysfunction (hypo and hyper), liver dysfunctionTremor, malaise, fatigue, GI upsets, dizziness, poor coordination, peripheral neuropathy, involuntary movementsLiver enzyme elevations are common but occur in patients with MI, HF, shock, multiple defibrillations, and so forth. It is unknown if elevations in liver enzymes are due to amiodarone or to associated conditions commonly present in these patientsHepatocellular necrosis has occurred in patients who received IV amiodarone at rates higher than recommended |
Give with meals to ↓ GI intoleranceBaseline chest x-ray, renal, liver, thyroid, and pulmonary function testsTakes several weeks to achieve therapeutic blood levels and for effects to decrease after stopping drugIs not dialyzable. Monitor K+ and Mg2+ levelsMonitor QTcDrug interactions: Additive proarrhythmic effects with many drugs (1A antiarrhythmics, phenothiazines, tricyclic antidepressants, thiazide diuretics, sotalol)↑ Protime with coumadin↑ Serum levels of digoxin, quinidine, procainamide, cyclosporineMay double flecainide levelCimetidine ↑ serum amiodarone levelsCholestyramine and phenytoin (Dilantin) ↓ serum amiodarone levelsAdditive effects on ↓ HR and ↓ AV conduction with β-blockers and Ca2+ blockers |
|
|
IV to PO transition: |
|
Special precautions with IV form: Physically incompatible with aminophylline, heparin, cefamandole, cefazolin, mezlocillin, sodium bicarbonateMust be delivered using a volumetric pump (not drop counter) because drop size is altered by drug |
|
|
Duration of IV |
PO dose |
|
|
<1 week |
800-1600 mg q.d. |
|
|
1-3 weeks |
600-800 mg q.d. |
|
|
>3 weeks |
400 mg q.d. |
|
|
Therapeutic level = 0.5-2 mcg/mLVery long half-life (26-107 days; average 53 days) |
Atenolol (Tenormin)(Cardioselective β-blocker) |
Ventricular rate control in atrial fib/flutterSlow conduction through AV node in AVNRT and CMT |
Initial dose: 12.5-25 mg PO q.d. Maintenance dose: 50-100 mg PO q.d.IV: 5 mg over 5 minutes, may repeat in 5 minutesHalf-life = 6-7 hours |
Hypotension, bradycardia, AV block. Diarrhea, wheezing, HF |
Cardioselective β-blocker used primarily for hypertension and anginaDrug interactions: Additive effects on HR, AV conduction, BP, and ↑ potential for HF when given with negative inotropic drugs, Ca2+ blockers, digoxin |
Atropine(Anticholinergic, parasympatholytic) |
Treatment of symptomatic bradycardia (sinus, junctional, AV block) and asystole |
Symptomatic bradycardia: 0.5 mg IV. May repeat q 3-5 minutes to a total of 3 mgAsystole: 1 mg IV, repeat q 3-5 minutes to a total vagolytic dose of 0.04 mg/kgMay be given down ET tube during cardiac arrest if no IV available: use 2-2.5 mgHalf-life = 2-5 hours |
CV: tachycardia, chest pain, VT/fibrillation (rare)CNS: drowsiness, confusion, dizziness, insomnia, nervousnessGI: dry mouth, ↓ GI motility, constipation, nauseaOther: urinary retention, hot flushed skin, rash |
Doses (0.5 mg may cause paradoxical bradycardiaCauses pupils to dilate (significant when checking pupils during cardiac arrest situation)Drug interactions: Incompatible with aminophylline, metaraminol, norepinephrine, pentobarbitol, sodium bicarbonate |
Digoxin |
Ventricular rate control in atrial fib/flutterRarely used as an antiarrhythmic anymoreUsed as an inotropic agent in HF |
PO loading dose: 0.5-1 mg divided into three or four doses at 6-8-hour intervalsPO maintenance dose: 0.125-0.5 mg q.d.IV loading dose: 0.5-1 mg divided into three or four doses given at 4-8-hour intervalsTherapeutic level = 0.8-2 ng/mLHalf-life = 36-48 hours |
CV: bradycardia, AV blockDigoxin toxicity: sinus exit block, AV block, AT with block, bidirectional VT, fascicular tachycardia, accelerated junctional rhythm, regularization of ventricular response to atrial fibVisual disturbances (halo vision), anorexia, nausea, vomiting, malaise, headache, weakness, disorientation, seizures |
Contraindicated in patients with WPWDigoxin toxicity is more common in the presence of hypokalemia, renal failure, pulmonary or thyroid disease, and in older peopleDrug interactions: The following drugs ↓ digoxin levels: cholestyramine, antacids, kaopectate, neomycin, sulfasalazine, para-aminosalicylateThe following drugs ↑ digoxin levels: Erythromycin, tetracycline, quinidine, amiodarone, verapamil, spironolactone, nicardipine, indomethacin |
Diltiazem (Cardizem)(Calcium channel blocker: nondihydropyridine, “heart rate lowering” Ca2+ blocker) |
Ventricular rate control in atrial fib/flutterSlow conduction through AV node in AVNRT and CMT |
120-360 mg/day in divided dosesIV: 0.25 mg/kg bolus over 2 minutesIf needed, repeat with 0.35 mg/kg over 2 minutesIV infusion: 5-15 mg/hTherapeutic level = 50-200 ng/mLHalf-life = 4-6 hours |
Bradycardia, heart block, HF, hypotension, flushing, angina, syncope, insomnia, ringing ears, edema, headache, nauseaLess depression of contractility than with verapamil but watch for HF |
Contraindicated in patients with accessory pathways (WPW, short PR syndrome)Drug interactions: Additive effects on HR, AV conduction, BP, and ↑ potential for HF when given with negative inotropic drugs, β-blockers, digoxin |
Disopyramide (Norpace)(Class IA antiarrhythmic) |
Used to prevent recurrence of VT or VFEffective in preventing atrial fib and flutterSlows conduction through accessory pathways |
Total daily dose = 400-800 mg in divided doses, usually 150 mg q 6 hoursSR form = 300 mg q 12 hoursTherapeutic level = 3-6 mcg/mLHalf-life = 4-10 hours |
Anticholinergic effects: dry mouth, urinary retention, constipation, precipitation or exacerbation of glaucomaCV: marked negative inotropic effects, HF, prolongs QT interval, proarrhythmic (less than quinidine or procainamide), ↑ SVR |
Monitor QT interval and watch for torsadesDrug Interactions: May potentiate effect of coumadinAdditive negative inotropic effects with β-blockers or Ca2+ blockers. Phenobarbitol, dilantin, rifampin ↓ disopyramide levels. Quinidine ↑ disopyramide level |
Dofetilide (Tikosyn)(Class III antiarrhythmic) |
Conversion of atrial fibrillation or flutter to NSR and maintenance of NSR after conversion |
Dose based on creatinine clearance: if normal renal function, 500 mcg b.i.d. If abnormal renal function, 250 mcg b.i.d.Do not give if creatinine clearance <20 mL/min Half-life = 9.5 hours |
TdP (up to 3% incidence), usually occurs within 3 days after initiating therapyHas no negative inotropic effects and does not lower BP |
Patient must be on telemetry during initiation of therapy or with increase in dosage (recommendation is for 3 days monitoring)Monitor QT interval every 2-3 hours: if QTc increases >15% or if QTc is >500 milliseconds, reduce dose. If QTc after second dose is >500 milliseconds, drug should be discontinuedDrug Interactions: Drugs that increase dofetilide levels include verapamil, ketoconazole, cimetidine, macrolide antibiotics, ritonavir, prochlorperazine, megestrolMaintain normal K+ and Mg2+ levels |
Epinephrine (Adrenalin) |
Treatment of any cardiac arrest situation requiring CPR: VF, pulseless VT, asystole, PEA |
1 mg IV bolus every 3-5 minutes during resuscitation effortsMay be given by way of ET tube if IV access not available: use 2-2.5 mgMay be infused at 2-10 mcg/min to maintain BP during symptomatic bradycardia |
CV: tachycardia, hypertension, arrhythmias, anginaCNS: restlessness, headache, tremor, strokeOther: nausea, ↓ urine output, transient tachypnea |
Drug Interactions: Has potential to cause arrhythmias when given with digoxin, other sympathomimetic agentsPhysically incompatible with aminophylline, ampicillin, cephapirin, sodium bicarbonate, and other alkaline solutions |
Esmolol (Brevibloc)(Cardioselective β-blocker) |
Rapid control of ventricular rate in atrial fib/flutter |
Loading infusion: 500 mcg/kg/min for 1 minuteMaintenance infusion: 50-100 mcg/kg/minUse dosing chart that comes with drug.β-Blocking plasma concentration = 0.15-1 mcg/mLHalf-life = 9 minutes |
Hypotension, dizziness, diaphoresis, nausea |
Short half-life so effects reversed within 10-20 minutes after stopping drug |
Flecainide (Tambocor)(Class IC antiarrhythmic) |
In absence of structural heart disease:Conversion of atrial fib to sinus rhythm and maintenance of NSRTreatment of SVT: AVNRT, CMTSlow conduction through accessory pathways in atrial fib or CMTLife-threatening ventricular arrhythmias (sustained VT) |
100-200 mg PO q 12 hoursTherapeutic level = 0.2-1 mcg/mL (Plasma levels do not correlate with efficacy, but incidence of CV toxicity greater when levels >1 mcg/mL)Half-life = 12-27 hours |
CV: marked proarrhythmia, marked negative inotropic effects (HF), bradycardia, heart blockCNS: blurred vision, dizziness, flushing, ringing ears, drowsiness, headache.Other: bad taste, constipation, edema, abdominal pain |
Drug interactions: May increase digoxin levelAdditive effects on HR, AV conduction, BP, and ↑ potential for HF when given with negative inotropic drugs, Ca2+ blockers, digoxinIncompatible with sodium bicarbonate, Lasix, Valium, thiopentalHigher mortality rate in post-MI patients when studied in CAST. Safest in patients with normal LV functionShould not be used in patients with recent MIProlongs QT interval, potential for proarrhythmia (TdP)Monitor for HFFull therapeutic effect may take up to 5 daysDrug Interactions: ↑ digoxin levels.Cimetidine, amiodarone, propranolol increase flecainide levelsAdditive negative inotropic effects with β-blockers, Ca2+ blockers, disopyramide |
Ibutilide (Corvert)(Class III antiarrhythmic) |
Conversion of atrial fib or flutter to sinus |
IV infusion of 1 mg over 10 minutesMay repeat same dose in 10 minutes if neededIn patients <60 kg: 0.01 mg/kgHalf-life = 6 hours |
Hypotension, VT, torsades, bundle-branch block, AV block, nausea, headache |
Prolongs QT interval: up to 6% incidence of torsades. Proarrhythmia usually occurs within 40 minutes. Monitor ECG continuously during administration and at least 4 hours afterConversion to NSR usually occurs within 20-30 minutes of infusionDrug interactions: Do not give other class I or class III agents within 4 hours |
Lidocaine (Xylocaine)(Class IB antiarrhythmic) |
Treatment of ventricular arrhythmias: VT, VFEffective for PVC suppression but PVC suppression not usually recommended |
For VT: 1 mg/kg IV bolus over 3 minutes followed by infusion at 2-4 mg/min. Repeat bolus of 0.5-0.75 mg/kg in 10 minutes to maintain therapeutic level. May repeat to total of 3 mg/kgFor VF or pulseless VT: 1.5 mg/kg IV bolus. May repeat with same amount and follow with infusion at 2-4 mg/minMay be given down ET tube during cardiac arrest if no IV available.Therapeutic level = 1.4-5 mcg/mLHalf-life of bolus = 10 minutesHalf-life once therapeutic level reached = 1.5-2 hours |
Side effects relatively rareCNS: lightheadedness, dizziness, tremor, agitation, tinnitus, blurred vision, convulsions, respiratory depression and arrestCV: bradycardia, asystole, hypotension, shock |
↓ Dose to half if liver disease or low liver blood flow (shock)Drug Interactions:β-Blockers and cimetidine increase lidocaine levelsGlucagon and isoproterenol may increase liver blood flow and ↓ lidocaine levels |
Magnesium |
May be useful for treatment or prevention of both supraventricular and ventricular arrhythmias after MI or cardiac surgery. Treatment of choice for TdP and may be useful in VF or pulseless VT refractory to other drugs |
1-2 g diluted in 10 mL D5W over 1-2 minutes. May be given IV push for VF or torsadesInfusion of 0.5-1 g/h for up to 24 hours |
CV: hypotension, bradycardia, heart block, cardiac arrestCNS: weakness, drowsiness, peripheral neuromuscular blockade, absent deep tendon reflexesOther: ↓ respiratory rate, respiratory paralysis |
Drug Interactions: CNS depression when used with general anesthetics, barbiturates, opiate analgesicsAdditive effects with neuromuscular blocking agentsIncompatible with calcium, sodium bicarbonate, ciprofloxacin |
Metoprolol (Lopressor)(Cardioselective β-blocker) |
Ventricular rate control in atrial fib/flutterSlow conduction through AV node in AVNRT and CMT |
PO: 100-450 mg q.d. in divided dosesIV: 5 mg q 2-5 minutes for three doses (used in acute MI)β-Blocking plasma concentration = 50-100 ng/mLHalf-life = 3-7 hours |
Hypotension, bradycardia, AV block |
Drug interactions: Additive effects on HR, AV conduction, BP, and ↑ potential for HF when given with negative inotropic drugs, Ca2+ blockers, digoxin |
Mexiletine (Mexitil)(Class IB antiarrhythmic) |
Acute and chronic treatment of symptomatic VTSometimes used in combination with Quinidine or sotalol to increase efficacyMay be useful in congenital LQTS |
PO loading dose = 400 mgMaintenance dose = 100-300 mg q 8 hours. Up to 400 mg q 8 hours if needed and no intolerable side effectsTherapeutic level = 0.5-2 mcg/mLHalf-life = 10-17 hours |
GI: nausea, vomiting, heartburn, anorexia, diarrheaCNS: tremor, dizziness, ataxia, slurred speech, paresthesias, seizures, hallucinations, emotional instability, insomnia, memory impairmentCV: bradycardia, hypotension, HF, proarrhythmia (rare compared to other agents)Other: thrombocytopenia, fever, rash, positive antinuclear antibody |
Often given in combination with other antiarrhythmics with increased effectiveness (quinidine, disopyramide, propafenone, amiodarone)Drug interactions: Phenobarbitol, dilantin, rifampin ↓ mexiletine levelsCimetidine ↑ mexiletine levelsMexiletine ↑ theophylline levels |
Procainamide (Pronestyl)(Class IA antiarrhythmic) |
Conversion of atrial fib to sinus and maintenance of NSRTreatment of AT, atrial flutter and fibSlows conduction through accessory pathways in WPWTreatment of monomorphic VT |
PO dose (regular release form): loading dose of 1,000-1,200 mg; maintenance dose 50 mg/kg/day in divided doses three to four times a day (never more than 6 hour between doses)SR forms: 750-1,500 mg q 6 hoursIV loading dose: 17 mg/kg at 20 mg/min. If rapid loading is needed, give 100-mg doses over 5 minutes to total of 1gIV drip 2-4 mg/minTherapeutic level = 4-10 mcg/mL (may be as high as 5-32 mg/L to prevent sustained VT)Half-life = about 3.5 hoursActive metabolite is NAPA: therapeutic level = 9-12 mg/L |
GI: nausea, vomiting, anorexiaCV: bradycardia, heart block, proarrhythmia (less than that with quinidine). Prolongs QT intervalHypotension. With IV useCNS: headache, insomnia, dizziness, psychosis, hallucinations, depressionLupus-like syndrome with long-term use (15%-25% of patients who take drug >1 year)Other: rash, fever, swollen joints, agranulocytosis, pancytopenia |
Monitor QT interval, QRS width, PR.Monitor NAPA level (active metabolite)Watch for hypotension with IV useDrug Interactions: Amiodarone, cimetidine, ranitidine increase procainamide levelsAlcohol ↓ procainamide levelsAdditive effects on conduction system disease when given with other class IA, class IC, tricyclic antidepressants, or Ca2+ blockers |
Propafenone (Rythmol)(Class IC antiarrhythmic, also has β-blocker effects) |
Conversion of atrial fib to sinus and maintenance of NSRSlow conduction through accessory pathwaysLife-threatening ventricular arrhythmias (sustained VT) |
150-300 mg t.i.d.Therapeutic level = 0.2-3 mcg/mLHalf-life = 2-10 hours in normal metabolizers, up to 32 hours in slow metabolizers |
GI: nausea, anorexia, constipation, metallic tasteCNS: dizziness, headache, blurred visionCV: HF, bradycardia, AV block, bundle-branch block, proarrhythmia |
Was not included in CAST but is same class as drugs shown to cause higher mortality post-MIWatch for proarrhythmiaDrug interactions: ↑ digoxin levels.Potentiates coumadinHas mild β-blocker and Ca2+ blocker effects↑ Cyclosporin levelsQuinidine and cimetidine increase propafenone levels |
Propranolol (Inderal)(Noncardioselective β-blocker) |
Ventricular rate control in atrial fib/flutterTreatment of SVT (slow AV node conduction): AVNRT, CMTEffective in some types of VT: exercise induced, digitalis inducedEffective in reducing incidence of VF and sudden death post-MI |
PO: 10-30 mg three to four times a dayIV: 1-3 mg at rate of 1 mg/minβ-Blocking plasma concentration = 50-100 ng/mLHalf-life = 3-5 hours |
GI: nausea, vomiting, stomach discomfort, constipation, diarrheaCNS: dreams, hallucinations, insomnia, depressionOther: bronchospasm, exacerbation of peripheral vascular disease, fatigue, hypoglycemia, impotence |
Drug interactions: Additive effects on HR, AV conduction, BP, and ↑ potential for HF when given with negative inotropic drugs, Ca2+ blockers, digoxin |
Quinidine(Class IA antiarrhythmic) |
Not used much anymore due to high incidence of proarrhythmiaConversion of atrial fib to NSR and maintenance of NSRMay be used for other SVTs: AT, AVNRT, accessory pathwaysHas been used for VT |
Sulfate: 200-400 mg q 6-8 hoursGluconate: 324 mg SR tabs, 1-2 q 8-12 hoursTherapeutic level = 2-6 mcg/mL Half-life = 7-9 hours |
GI: nausea, diarrhea, abdominal painCV: hypotension, bradycardia, tachycardias, TdP, HF prolongs QTc interval, proarrhythmiaCNS: cinchonism (tinnitus, hearing loss, confusion, delirium, visual disturbances, psychosis) |
Give with food.Monitor QT interval, QRS width, PRWatch for proarrhythmia (torsades)IV use rare (hypotension)Drug Interactions:↑ Digoxin levelsIncreased bleeding when used with coumadin |
|
|
|
|
Other: fever, headache, rashes, leukopenia, thrombocytopenia |
Dilantin, phenobarbital, rifampin, nifedipine, sodium bicarbonate, thiazide diuretics all ↓ quinidine levelsCimetidine, amiodarone, verapamil all increase quinidine levels |
Sotalol (Betapace)(Class III antiarrhythmic; and noncardioselective β-blocker) |
Maintenance of NSR after conversion from atrial fib/flutter. Not recommended for pharmacological conversion of atrial fib/flutterTreatment of SVTSlow conduction through accessory pathwaysLife-threatening VT, VF |
Should be used only in patients without heart disease or bradycardia when serum electrolytes are normalContraindicated if baseline QTc >450 milliseconds or CrCl <40 mL/min.80 mg b.i.d. × 3 days, then 160 mg b.i.d. × 3 days. Decrease dose or discontinue if QT prolongs to 500 milliseconds or moreMaximum recommended dose is 160 mg b.i.dTherapeutic level = 1-4 mcg/mL (not clinically useful)Half-life = 8-17 hours with normal renal function; up to 6 days with severe renal failure |
CV: bradycardia, heart block, HF, proarrhythmiaOther: bronchospasm, fatigue, weakness, GI symptoms, dizziness, dyspnea, hypotension |
Prolongs QT interval, potential for proarrhythmia. Monitor QT 2-4 hours after each dose when initiating therapyWatch for bradycardia, AV block, and new or worsening HF |
Verapamil (Calan)(Calcium channel blocker: nondihydropyridine “heart rate lowering” Ca2+ blocker) |
Ventricular rate control in atrial fib/flutterSlow conduction through AV node in AVNRT and CMT |
PO: 80-120 mg t.i.d. or q.i.d.IV: 2.5-5 mg over 2 minutesMay repeat with 5-10 mg if neededTherapeutic level = 80-400 ng/mLHalf-life = 3-7 hours |
Bradycardia, heart block, HF, hypotension, fatigue, headache, edema, constipation |
Contraindicated in patients with accessory pathways (WPW, short PR syndrome)Drug interactions: Additive effects on HR, AV conduction, BP, and ↑ potential for HF when given with negative inotropic drugs, Ca2+ blockers, digoxin |
CAST, Cardiac Arrhythmia Suppression Trial; CMT, circus movement tachycardia using an accessory pathway; ET, endotracheal, NAPA, N-acetylprocainamide; NSR, normal sinus rhythm, PEA, pulseless electrical activity, SVR, systemic vascular resistance, SR, sustained release. |
↑ = increases, ↓ = decreases. |