Digoxin Drug Level
Does this test have other names?
Therapeutic digoxin monitoring, dig level
What is this test?
This test measures the amount of the heart drug digoxin in your blood.
Digoxin is a drug that helps your heart pump better when you have an irregular or
rapid heartbeat. This heartbeat is often caused by atrial fibrillation. Digoxin may
also be given to you if you have congestive heart failure (CHF).
When you take digoxin, it's important that the drug be at the right level for you
to get the help you need from it. Your healthcare provider may need to change your
dose if your levels are too high or too low.
Why do I need this test?
You may need this test to have your digoxin level checked when you first start treatment.
This is to make sure you are taking the right dose. The dose level that works best
for most people may be called the therapeutic range. A digoxin dose is not the same
for everyone, so your healthcare provider may need to change your dose over time.
You may need this test to:
Find your therapeutic dose of digoxin after you begin taking the drug
Check the drug level regularly to make sure you keep getting a therapeutic dose
See whether certain symptoms you are having may be related to your digoxin level
What other tests might I have along with this test?
Your healthcare provider may also order other tests if you have signs or symptoms
that may mean your digoxin level is too high or too low. These tests include an electrocardiogram,
or ECG. Your provider may also order tests to check your kidney health if you have
kidney problems. He or she may also order tests to check your blood potassium and
magnesium levels. Kidney problems and low levels of potassium or magnesium in the
blood may lead to digoxin overdose.
What do my test results mean?
Many things may affect your lab test results. These include the method each lab uses
to do the test. Even if your test results are different from the normal value, you
may not have a problem. To learn what the results mean for you, talk with your healthcare
Results are given in nanograms per milliliter (ng/mL).
If you are taking digoxin because of an irregular heartbeat, your ideal range may
be between 1.5 and 2.5 ng/mL. But this range varies widely. This is because the test
is more commonly used to check for toxicity when treating an irregular heart beat
instead of to find out how well the drug is working as a treatment.
If you have CHF, the ideal range may be lower. When used for CHF, the target range
for this test is important to find out both how well the drug is working as treatment
and to avoid the risk for toxicity.
If your digoxin level is outside the therapeutic range, your healthcare provider may
raise or lower your digoxin dose.
If you have CHF and your digoxin levels are below the normal treatment range, you
may develop symptoms of persistent heart failure:
Digoxin levels above the normal treatment level may cause:
Very high levels of digoxin can cause a condition called digoxin toxicity. This may
require treatment with a medicine to block the effects of digoxin. Digoxin side effects
can occur even when levels are considered to be within normal limits. It's important
to report any new symptoms to your healthcare provider.
How is this test done?
The test requires a blood sample, which is drawn through a needle from a vein in your
Does this test pose any risks?
Taking a blood sample with a needle carries risks that include bleeding, infection,
bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight
stinging sensation or pain. Afterward, the site may be slightly sore.
What might affect my test results?
Taking digoxin within 6 to 12 hours before this test can affect your results.
Many other medicines can also affect your digoxin level. These include antacids, drugs
that lower cholesterol, over-the-counter medicines for diarrhea, bulk laxatives, and
nutritional supplements. Foods high in fiber can also affect your results.
How do I get ready for this test?
Ask your healthcare provider when you should stop taking digoxin before the test.
In addition, make sure your provider knows about all medicines, herbs, vitamins, and
supplements you are taking. This includes medicines that don't need a prescription
and any illicit drugs you may use.