Description and indication for use
Amiodarone is a
Class III anti-arrhythmic agent, prolonging the action potential duration and
hence refractory period of atrial, nodal and ventricular tissues. Amiodarone has a very broad spectrum of
activity, and is also a potent vasodilator.
It is indicated
in severe cases of tachyarrhythmias, supraventricular nodal and ventricular
tachycardias, and atrial flutter. Due to
frequent and severe toxicity, amiodarone should be used only in the treatment
of life-threatening arrhythmias.
Dose
IV:
2.5 mg/kg 6 hourly, extending the interval
over time.
Dose must be titrated against therapeutic
effect.
Reconstitution/Dilution
Ampoule = 150 mg in 3 mL (50 mg/mL). Not
Ward Stock.
For IV use:
Withdraw 0.2 mL of 50 mg/mL solution and
add to 0.8 mL of Glucose 5% in a second 1 mL syringe = 10 mg/mL.
Take 1 mL of this solution and add 4 mL of Glucose
5% in a 5 mL syringe = 10 mg in 5 mL = 2 mg/mL.
Discard excess volume to obtain required
dose or withdraw required dose using another 10 mL syringe.
Route and method of administration
IV:
Give as an infusion over 1 hour - via
infusion syringe pump.
**Draw up an additional syringe of glucose
5% (3 mL) in a 10 mL syringe for a flush.
After infusion completed, change to syringe
of glucose 5% and infuse (2 mL) at same rate as the Amiodarone was infusing
(set appropriate volume limit).
Discard syringes and line following completion
of drug and flush.
If repeated doses are anticipated, where possible,
administration via central venous catheter (CVC) is recommended due to
peripheral administration causing inflammation of the vein.
Not
for IM use.
Side effects
Hypotension, bradycardia, atypical
ventricular tachycardia.
Hot flushes, sweating.
Nausea, constipation.
Hepatotoxicity, abnormal liver function
tests.
Nephrotoxicity, raised serum creatinine.
Abnormal thyroid function tests,
hyperthyroidism/hypothyroidism.
Hyperglycaemia.
Pulmonary toxicity with long term use.
Thrombophlebitis.
Photosensitivity.
Blue-grey discoloration of skin.
Special precautions
CAUTION in patients with left ventricular dysfunction.
CAUTION in patients with hypotension.
CAUTION in patients with thyroid dysfunction.
Marked cardiomegaly is a relative
contra-indication.
Incompatibilities
Amiodarone is incompatible with many drugs.
Amiodarone must not be diluted with sodium
chloride 0.9%.
Do not administer with TPN solution or
Intralipid.
Recommended to be administered alone or contact
Pharmacy for further information.
Drug interactions
| Digoxin | Plasma levels of digoxin are increased. A reduced dose of digoxin is recommended. |
| Phenytoin | Plasma levels of phenytoin are increased. Recommended that phenytoin levels be closely monitored. Effectiveness of amiodarone may also be reduced. |
| Sotalol, betablockers | Can result in symptomatic bradycardia and sinus arrest. Hypotension as a side effect can be severe when the combination is used. |
| Theophylline | Plasma levels of theophylline may be increased. Theophylline levels should be monitored. |
Nursing responsibilities
Continuous cardiorespiratory monitoring.
Monitor blood pressure.