At a glance
Why get tested?
To determine if the concentration of digoxin in your blood is at a therapeutic level or to detect toxic levels
When to get tested?
At least one week after the start of digoxin therapy and at regular intervals to ensure that drug levels are within therapeutic range and are not low or at toxic concentrations
A blood sample drawn from a vein in your arm
Test preparation needed?
No special test preparation required but the sample is usually drawn not long before the next dose is due (this is called a trough level).
What is being tested?
Digoxin is a drug used to treat heart failure and abnormal heart rhythms. This test measures the amount of digoxin in the blood. Heart failure, including congestive heart failure (CHF), causes the heart to become less effective at circulating blood. As a result, blood backs up into the legs, hands, feet, lungs and liver, causing swelling, shortness of breath and fatigue.
Digoxin is prescribed to alleviate some of heart failure. It strengthens the contractions of the heart and helps it to pump blood more efficiently. Digoxin also helps control the heart rate and abnormal heart rhythms known as arrhythmias. It will not cure heart failure or arrhythmias, which are chronic conditions, but can help to manage the symptoms along with diet, exercise, and other medications.
Digoxin levels need to be monitored because digoxin is a drug that has a narrow safety range. If the level in the blood is too low, symptoms may recur. If the level is too high, may occur with possible side effects such as:
- blurred vision or seeing yellow or green halos
- irregular heartbeat, or
- difficulty breathing.
Digoxin dosage may be adjusted based on levels measured.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No special preparation is needed, but timing of the sample for testing is important. The sample should be drawn at least 6-8 hours after the last dose.
How long will I need to be on digoxin?
Digoxin is usually taken for your lifetime. Very rarely is it ever discontinued.
Who orders digoxin tests?
Your primary doctor may order the test, but it also may be monitored by a cardiologist.
Can I test my digoxin level at home?
No, there are no home tests developed to date. Digoxin testing requires special handling and instruments for accurate results.