Digoxin (Serum) Level
This test measures the amount of digoxin, a medication used to treat certain heart conditions, in your blood serum. It helps doctors monitor your dose to avoid harmful levels.
["Digoxin levels help ensure your heart medication is working safely and effectively."]
Key facts at a glance
- LOINC
- 110653-3
- Short code
- Digoxin Msmt SerPl
- Synonyms
- Digoxin Msmt SerPl
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.5
- Ref high
- 2
- Critical range
- — – 4 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order a digoxin level test if you’re taking digoxin (Lanoxin) to manage heart rhythm issues like atrial fibrillation or heart failure. It’s also used to check if your dose is too high or too low, especially if you have kidney problems or take other medications that interact with digoxin.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if your lab uses a specific method. Bring a list of all medications you’re taking, including over-the-counter drugs and supplements, as they can affect results.
During the Test
A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause discomfort. The blood sample is sent to a lab for analysis.
What the Results Mean
Results are reported in nanograms per milliliter (ng/mL) or micrograms per liter (µg/L). Your doctor will interpret the results based on your medical history, symptoms, and other medications. Very high levels can cause toxic side effects, while very low levels may mean your medication isn’t working properly.
Reference range
Therapeutic: 0.5-2.0 ng/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Digoxin Level
Frequently asked questions
How often should I get this test?
What happens if my digoxin level is too high?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy