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Digoxin serum concentration (mass concentration)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of digoxin, a medication used to treat certain heart conditions, in your blood serum.

Quick summary

["Digoxin levels help ensure your medication dose is safe and effective for your heart health."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
10535-3
Short code
Digoxin SerPl-mCnc
Synonyms
Digoxin SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
17
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 healthcare provider may order this test if you’re taking digoxin (Lanoxin) to manage conditions like heart failure or irregular heart rhythms. It helps monitor whether your dose is too high or too low, preventing side effects or worsening your condition.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or vein to draw a blood sample. The process usually takes a few minutes, and you’ll feel a brief pinch or pressure.

How the Results Are Used

Results guide your doctor in adjusting your digoxin dose if needed. Very high levels can cause symptoms like nausea, vomiting, or irregular heartbeat, while very low levels may mean your heart isn’t responding well to the medication.

Possible Side Effects or Risks

Rarely, blood tests can cause mild bruising, swelling, or discomfort at the injection site. If you experience dizziness, confusion, or severe stomach pain, contact your doctor immediately.

Reference range

NCBI: NSE 0-17 ng/mLN/A

Specimen: serum

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.

Digoxin levels are critical for patients with heart conditions because it’s a narrow therapeutic window medication. Too much can lead to toxicity (e.g., arrhythmias), while too little may reduce its effectiveness. Regular monitoring helps balance safety and treatment goals.

Short name

Digoxin Level

Frequently asked questions

What causes digoxin levels to change?
Digoxin levels can fluctuate due to factors like diet (e.g., high potassium from foods like bananas), kidney function (which filters the drug), other medications (e.g., diuretics), or illness (e.g., dehydration). Your doctor will consider these when interpreting results.
How often should I get this test?
Frequency depends on your condition and dose. Some patients need testing weekly or monthly, while others may only need it every few months. Follow your doctor’s schedule—don’t skip it without approval.
Can I eat or drink before the test?
You can eat and drink normally unless instructed otherwise. Avoid alcohol or large amounts of caffeine before the test, as they may slightly affect blood chemistry, but this rarely impacts digoxin levels directly.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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