A blood sample is needed. For information on how this is done, see: Venipuncture
How to prepare for the test
Consult your health care provider about the need to take (or not take) usual medications before the test.
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
The main purpose of this test is to monitor patients taking digoxin in order to determine the best drug dosage and prevent side effects.
Monitoring of drug levels is important in people taking digitalis medications such as digoxin, because the difference between therapeutic levels and harmful levels is small.
Normal values range from 0.8 to 2.0 nanograms per milliliter.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results mean
Abnormal results may mean you are getting too little or too much of the medication.
A very high value could mean that you have or are likely to develop digoxin overdose (toxicity).
What the risks are
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Michael A. Chen, MD, PhD, Assistant Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.