McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 4 5 Antiarrhythmic agents

TABLE 45.1

DRUGS IN FOCUS Antiarrhythmic agents (continued)

Drug name

Dosage/route

Usual indications

Class I antiarrhythmics (continued) Class Ib lignocaine (Xylocaine)

Adult: 300 mg of 10% solution IM; 50- to 100-mg IV bolus at the rate of 20–50 mg/ minute; 1- to 4-mg/minute IV infusion Paediatric: safety and efficacy not established; 1 mg/kg IV followed by IV infusion 30 mcg/kg per minute has been recommended

Treatment of life-threatening ventricular arrhythmias during myocardial infarction or cardiac surgery; also used as bolus injection in emergencies when monitoring is not available to document exact arrhythmia Treatment of life-threatening ventricular arrhythmias in adults; prevention of paroxysmal atrial tachycardia (PAT) in symptomatic people with no structural heart defect Treatment of life-threatening ventricular arrhythmias in adults; prevention of PAT in symptomatic people with no structural heart defect Short-term management of supraventricular tachycardia in adults and tachycardia that is not responding to other measures Treatment of supraventricular tachycardias caused by digoxin or catecholamines in adults; also used as an antihypertensive, antianginal and antimigraine headache drug Treatment of adults with life-threatening ventricular arrhythmias not responding to any other drug; preferred antiarrhythmic in Advanced Cardiac Life Support protocol Treatment of adults with life-threatening ventricular arrhythmias not responding to any other drug IV to treat paroxysmal supraventricular tachycardia in adults IV to treat paroxysmal supraventricular tachycardia; temporarily controls the ventricular response to rapid atrial rates

Class Ic flecainide (Flecatab, Tambocor)

50–100 mg PO q 12 hours; reduce dose as needed with older people or people with renal impairment

propafenone (Rytmonorm)

150–300 mg PO based on the individual’s response; start with lower dose and increase slowly with older people

Class II antiarrhythmics esmolol (Brevibloc)

Loading dose of 500 mcg/kg per minute IV, then 50 mcg/kg per minute for 4 minutes, maintain with IV infusion 100 mcg/kg per minute

10–30 mg PO t.d.s. to q.i.d.

propranolol (Inderal, Deralin)

Class III antiarrhythmics amiodarone (Aratac, Cordarone X, Cardinorm)

800–1,600 mg/day PO in divided doses for 1–3 weeks, then 600–800 mg/day PO for 1 month, reduce to 400 mg/day PO if rhythm is stable 1,000 mg IV over 24 hours; then 540 mg IV at 0.5 mg/minute for 18–96 hours

sotalol (Cardol, Sotacor)

80 mg/day PO, may be titrated to 240–320 mg/day PO; reduce dose in people with renal impairment

Class IV antiarrhythmics diltiazem (Cardizem)

30 mg PO q.i.d. before meals and at bedtime, increased to maximum 360 mg/day PO Adult: 5–10 mg IV over 2 minutes, may repeat with 10 mg in 30 minutes if needed Paediatric: 0.1–0.3 mg/kg IV over 2 minutes, do not exceed 5 mg per dose; may repeat in 30 minutes if needed 6 mg IV as a rapid bolus over 1–2 seconds; may repeat with 12-mg IV bolus after 1–2 minutes if needed, may be repeated a second time if needed Adult: 0.75- to 1.25-mg PO loading dose, then 0.125–0.25 mg/day PO or 0.125- to 0.25-mg IV loading dose, and then 0.125–0.25 mg/day PO Paediatric: 10- to 50-mcg/kg loading dose PO or 8- to 50-mcg/kg loading dose IV, based on age; then maintenance dose of 25%–35% of loading dose

verapamil (Anpec, Cordilox SR, Isoptin)

Other antiarrhythmics adenosine (Adenocor, Adenoscan)

Treatment of supraventricular tachycardias, including those caused by the use of alternative conduction pathways in adults

digoxin (Lanoxin)

Treatment of atrial flutter, atrial fibrillation, paroxysmal atrial tachycardia