Cardiac Glycosides - Digoxin Flashcards
What are the actions of Digoxin?
Inhibits active transport of Na+ and K+ across myocardial cell membrane, and thus the sodium pump. It increases force of cardiac contraction, increasing cardiac output, and decreases conduction through the heart, especially through the AV node, and in turn, decreasing the heart rate.
What is lanoxin? What does the difference in name mean?
It is digoxin.
Digoxin is measured in micrograms whilst lanoxin is measured in milligrams.
What is the indication for digoxin?
For treating heart failure and cardiac arrthymias. This includes:
- atrial fibrillation
- atrial flutter
- atrial tachycardia
Explain what digoxin does during atrial fibrillation.
Slows down the ventricular rate by increasing the refractory period of he AV junction, slowing conduction at this site.
Name five adverse effects of digoxin.
- bradycardia
- ectopic beats
- bigeminy (two beats together)
- heart block
- headache
- confusion
- nightmares
- disturbed colour vision
Name six signs of digoxin toxicity.
- bradycardia
- nausea
- vomiting
- facial pain
- weakness
- abdominal pain
- bad dreams
- confusion
- hallucinations
Explain the normal dose range for digoxin.
62.5-250 mcg
- oral or IV
- half life of 20-50 hours with normal renal function
- loading doses can be implemented in acute situations of AF
What must you do every time you administer digoxin?
Take a pulse. If the pulse rate is below 60 then you withhold the dose and call the doctor.
Name five care considerations for digoxin.
- has a narrow therapeutic range, so needs monitoring through serum levels
- prior to administration, pulse rate must be checked
- commonly prescribed to the elderly, so may need a lower dose due to age
- hypokalaemia can induce toxicity, so should monitor for signs and serum urea and electrolytes
- monitor vital signs closely, including cardiac rate and rhythm
- patient medication (condition, medication, monitoring)
- caution in those with renal impairment
