AmiodaroneNursing considerations

Side effects by what to assess

Sources: [1][2][3][4][5][6][7][8][9][10][11]

ALT (liver enzyme)

Why

Hepatic injury

When

Baseline and periodically; closely during IV therapy

Act on

Above three times normal, or double a raised baseline: reduce or stop

Normal

4 to 36 U/L.

Sources: [1][2][3][4]

Blood pressure

Why

Hypotension during IV infusion

When

Closely, especially in the first hours of infusion

Act on

Slow the infusion; add vasopressors, inotropes, or fluids

Normal

Below 120/80 mm Hg.

Sources: [1][2]

ECG (rhythm and QT interval)

Why

QTc prolongation, bradycardia, AV block, proarrhythmia

When

Continuous when starting; during IV infusion

Act on

Bradycardia or AV block on IV: slow or stop the infusion

Sources: [1][2][3]

Heart rate

Why

Bradycardia

When

Regularly; closely with beta blockers, calcium channel blockers, digoxin, or sofosbuvir

Act on

Symptomatic bradycardia may need a pacemaker

Normal

60 to 100 beats per minute in adults at rest.

Sources: [1][2][3]

INR (prothrombin time)

Why

Warfarin interaction

When

Closely when amiodarone is started with warfarin

Act on

Cut the warfarin dose by one-third to one-half

Normal

INR 0.8 to 1.1 when not on a blood thinner. On warfarin, the usual target is 2.0 to 3.0.

Sources: [1][2]

Magnesium

Why

Low magnesium worsens QT prolongation and torsade risk

When

Before starting

Act on

Correct before starting

Normal

1.7 to 2.2 mg/dL.

Sources: [1][2]

Potassium

Why

Low potassium worsens QT prolongation and torsade risk

When

Before starting and with diuretics or diarrhea

Act on

Correct before starting

Normal

3.7 to 5.2 mEq/L.

Sources: [1][2][3]

TSH (thyroid-stimulating hormone)

Why

Hypothyroidism or hyperthyroidism

When

Before starting and periodically, especially in older adults or with thyroid disease

Act on

Treat; for hypothyroidism, reduce or stop amiodarone and add thyroid hormone

Normal

0.4 to 4.8 µU/mL.

Sources: [1][2][3]

High-alert status

High-alert medication (IV only). IV antiarrhythmics, with amiodarone named, are on the ISMP acute care high-alert list. Oral amiodarone is not listed.

Sources: [1]

Narrow therapeutic index

The label does not describe a narrow therapeutic index or direct dosing by measured blood levels of the drug.

Sources: [1][2]

Boxed warning

Oral Pacerone: pulmonary, hepatic, and cardiac toxicity. Use only for the labeled life-threatening arrhythmias, after other agents. Lung toxicity occurs in up to 17% in some series and is fatal about 10% of the time; get a baseline chest X-ray and pulmonary function tests and repeat the X-ray every 3 to 6 months. Liver injury can be fatal; check transaminases and reduce or stop if they rise above three times normal. It can worsen arrhythmias, so start it where continuous ECG and resuscitation are available. The Nexterone IV label has no boxed warning.

Sources: [1]

Antidote or reversal

No antidote. Monitor rhythm and blood pressure. Treat bradycardia with a beta-agonist or pacing, and hypotension with inotropes, vasopressors, and volume; for IV overdose, also slow the infusion. Monitor liver enzymes. Neither amiodarone nor its metabolite is removed by dialysis.

Sources: [1][2]

Patient teaching

• Report cough, shortness of breath, wheezing, or coughing blood right away
• Report yellow skin or eyes, dark urine, or upper belly pain
• Report a slow, fast, or irregular heartbeat, dizziness, or fainting
• Get regular eye exams; report halos, blurred vision, or vision loss
• Use sunscreen and protective clothing; skin may turn blue-gray
• Avoid grapefruit juice and St. John's wort
• Do not breastfeed; report pregnancy
• Effects and interactions can last for months after stopping; tell every provider

Sources: [1][2][3]

Sound-alike and look-alike names

• amiodarone and amantadine

Sources: [1]

Adult dose

Oral, life-threatening VF or unstable VT

Load 800 to 1600 mg/day until response, usually 1 to 3 weeks. Then 600 to 800 mg/day for 1 month, then maintenance, usually 400 mg/day. Use the lowest effective dose.

IV, VF or unstable VT

Load 150 mg in 10 minutes (15 mg/min), then 360 mg over 6 hours (1 mg/min), then 0.5 mg/min (540 mg) for the remaining 18 hours. After 24 hours, continue 0.5 mg/min (720 mg per 24 hours). Repeat 150 mg over 10 minutes for breakthrough VF or VT.

IV to oral switch

After less than 1 week of IV: 800 to 1600 mg oral daily. After 1 to 3 weeks: 600 to 800 mg. After more than 3 weeks: 400 mg.

Sources: [1][2][3][4]

Renal adjustment

None. Renal impairment does not change amiodarone or metabolite levels, and urinary excretion is negligible. Not dialyzable.

Sources: [1]

Hepatic adjustment

No defined dose change. It is cleared by the liver and can itself injure the liver, so check transaminases at baseline and periodically, and reduce or stop if they exceed three times normal or double from a raised baseline.

Sources: [1][2]

Mechanism

Mainly a class III antiarrhythmic: it blocks potassium channels and lengthens the action potential and refractory period in all heart tissue. It also has class I (sodium channel), class II (antisympathetic), and class IV (calcium channel) effects, slowing the sinus rate and AV node. Expect PR and QT prolongation of about 10% and sinus rate slowing of 15% to 20%.

Sources: [1]