Mosby's 2014 Nursing Drug Reference (33 page)

Canada only   Side effects:
italics
= common;
bold
= life-threatening   
Nurse Alert

HIGH ALERT
amiodarone (Rx)

(a-mee-oh′da-rone)

Cordarone, Nexterone, Pacerone

Func. class.:
Antidysrhythmic (class III)

Chem. class.:
Iodinated benzofuran derivative

Do not confuse:
amiodarone
/Inamrinone
Cordarone
/Inocor

ACTION:

Prolongs duration of action potential and effective refractory period, noncompetitive α- and β-adrenergic inhibition; increases PR and QT intervals, decreases sinus rate, decreases peripheral vascular resistance

USES:

Hemodynamically unstable ventricular tachycardia, supraventricular tachycardia, ventricular fibrillation not controlled by 1st-line agents

Unlabeled uses:
Atrial fibrillation treatment/prophylaxis, atrial flutter, cardiac arrest, cardiac surgery, CPR, heart failure, PSVT, Wolff-Parkinson-White (WPW) syndrome

CONTRAINDICATIONS:

Pregnancy (D), breastfeeding, neonates, infants, severe sinus node dysfunction, hypersensitivity, cardiogenic shock

 

Black Box Warning:

2nd-3rd degree AV block, bradycardia

Precautions:
Children, goiter, Hashimoto’s thyroiditis, electrolyte imbalances, CHF, respiratory disease

 

Black Box Warning:

Severe hepatic disease, cardiac arrhythmias, pneumonitis, pulmonary fibrosis

DOSAGE AND ROUTES
Calculator
Ventricular dysrhythmias

• Adult: PO
Loading dose 800-1600 mg/day for 1-3 wk then 600-800 mg/day for 1 mo, maintenance 400 mg/day;
IV
loading dose (1st rapid) 150 mg over the first 10 min then slow 360 mg over the next 6 hr, maintenance 540 mg given over the remaining 18 hr, decrease rate of the slow inf to 0.5 mg/min

• Child (unlabeled):
PO
Loading dose 10-15 mg/kg/day in 1-2 divided doses for 4-14 days then 5 mg/kg/day

• Child and infant:
IV/INTRAOSSEOUS
(during CPR) 5 mg/kg as a bolus (PALS guidelines)

Perfusion tachycardia

•Adult: IV
5 mg/kg loading dose given over 20-60 min

Supraventricular dysrhythmias (atrial fibrillation, atrial flutter, PSVT, WPW syndrome) (unlabeled)

• Adult: PO
1.2-1.8 g/day divided until a total of 10 g has been given, then 200-400 mg/day (class IIa recommendation);
IV
5-7 mg/kg over 30-60 min, then 1.2-1.8 g as
CONT IV INF
or in divided PO doses until 10 g, then 200-400 mg/day (class IIa recommendation)

• Child and infant:
PO
10-20 mg/kg/day in divided doses for 7-10 days, then 5-10 mg/kg/day once daily

Available forms:
Tabs 100, 200, 400 mg; inj 50 mg/ml

Administer:
PO route

• 
May be used with/without food but be consistent

IV, direct route

• 
Peripheral:
max 2 mg/ml for more than 1 hr; preferred through central venous line with in-line filter; concentrations of more than 2 mg/ml should be given by central line

• 
Cardiac arrest:
give 300 bol; may repeat 150 mg after 3-5 min

Intermittent IV INF route

• 
Rapid loading:
add 3 ml (150 mg), 100 ml D
5
W (1.5 mg/ml), give over 10 min

• 
Slow loading:
add 18 ml (900 mg), 500 ml D
5
W (1.8 mg/ml), give over next 6 hr

Continuous IV INF route

• 
After 24 hr, dilute 50 ml to 1-6 mg/ml, give 1-6 mg/ml at 1 mg/min for the 1st 6 hr, then 0.5 mg/min

Y-site compatibilities:
Amikacin, clindamycin, DOBUTamine, DOPamine, doxycycline, erythromycin, esmolol, gentamicin, insulin, isoproterenol, labetalol, lidocaine, metaraminol, metroNIDAZOLE, midazolam, morphine, nitroglycerin, norepinephrine, penicillin G potassium, phenylephrine, potassium chloride, procainamide, tobramycin, vancomycin

Solution compatibility:
D
5
W, 0.9% NaCl

SIDE EFFECTS

CNS:
Headache, dizziness
, involuntary movement,
tremors, peripheral neuropathy
, malaise,
fatigue
, ataxia,
paresthesias
, insomnia

CV:
Hypotension, bradycardia
,
sinus arrest, CHF, dysrhythmias, SA node dysfunction, AV block,
increased defibrillation energy requirement

EENT:
Blurred vision, halos, photophobia,
corneal microdeposits
, dry eyes

ENDO:
Hypo
/hyperthyroidism

GI:
Nausea, vomiting
, diarrhea, abdominal pain,
anorexia, constipation
,
hepatotoxicity

GU:
Epididymitis, ED

INTEG:
Rash, photosensitivity, blue-gray skin discoloration, alopecia, spontaneous ecchymosis,
toxic epidermal necrolysis,
urticaria,
pancreatitis,
phlebitis (IV)

MISC:
Flushing, abnormal taste or smell, edema, abnormal salivation, coagulation abnormalities

MS:
Weakness, pain in extremities

RESP:
Pulmonary fibrosis/toxicity,
pulmonary inflammation,
ARDS; gasping syndrome if used with neonates

PHARMACOKINETICS

PO:
Onset 1-3 wk, peak 2-7 hr, half-life 26-107 days, metabolized by liver (CYP3A4, CYP2C8), excreted by kidneys, 99% protein binding

INTERACTIONS

Increase:
QT prolongation—azoles, fluoroquinolones, macrolides

Increase:
amiodarone concentrations, possible serious dysrhythmias-protease inhibitors, reduce dose

Increase:
myopathy—HMG-CoA reductase inhibitors

Increase:
bradycardia—β-blockers, calcium channel blockers

Increase:
levels of cycloSPORINE, dextromethorphan, digoxin, disopyramide, flecainide, methotrexate, phenytoin, procainamide, quiNIDine, theophylline, class I antidysrhythmics

Increase:
anticoagulant effects—warfarin

Drug/Food

• 
Toxicity: grapefruit juice

Drug/Lab Test

Increase:
T
4
, ALT, AST, GGT alk phos, cholesterol, lipids, PT, INR

Decrease:
T
3

NURSING CONSIDERATIONS
Assess:

 

Black Box Warning:

Pulmonary toxicity: dyspnea, fatigue, cough, fever, chest pain; product should be discontinued; for ARDS, pulmonary fibrosis, crackles, tachypnea, increased at higher doses, toxicity is common

 

Black Box Warning:

ECG continuously to determine product effectiveness; measure PR, QRS, QT intervals; check for PVCs, other dysrhythmias, B/P continuously for hypo/hypertension; report dysrhythmias, slowing heart rate; monitor amiodarone level: therapeutic 1-2.5 mcg/ml; toxic >2.5 mcg/ml

• 
Electrolytes (sodium, potassium, chloride); hepatic studies: AST, ALT, bilirubin, alk phos; for dehydration, hypovolemia, monitor PT, INR if using warfarin

• 
Chest x-ray, thyroid function tests

• 
CNS symptoms: confusion, psychosis, numbness, depression, involuntary movements; product should be discontinued

• 
Hypothyroidism:
lethargy; dizziness; constipation; enlarged thyroid gland; edema of extremities; cool, pale skin

• 
Hyperthyroidism:
restlessness; tachycardia; eyelid puffiness; weight loss; frequent urination; menstrual irregularities; dyspnea; warm, moist skin

• 
Ophthalmic exams at baseline and periodically (PO); to prevent corneal deposits, use methylcellulose

• 
Cardiac rate, respirations: rate, rhythm, character, chest pain; start with patient hospitalized and monitored up to 1 wk; for rebound hypertension after 1-2 hr

Evaluate:

• 
Therapeutic response: decrease in ventricular tachycardia, supraventricular tachycardia, fibrillation

Teach patient/family:

• 
To take this product as directed; to avoid missed doses; not to use with grapefruit juice; do not discontinue abruptly

• 
To use sunscreen or stay out of sun to prevent burns; that dark glasses may be needed for photophobia

• 
To report side effects immediately; more common at high dose

• 
That skin discoloration is usually reversible

TREATMENT OF OVERDOSE:

O
2
, artificial ventilation, ECG, administer DOPamine for circulatory depression, administer diazepam, thiopental for seizures, isoproterenol

Canada only   Side effects:
italics
= common;
bold
= life-threatening   
Nurse Alert

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