Digoxin nmol/L → ng/mL
Convert digoxin from nmol/L to ng/mL
Sources last checked: 2026-11-03
Digoxin nmol/L → ng/mL
Convert digoxin from nmol/L to ng/mL
Converts units only; reference ranges depend on the laboratory, the assay and the patient.
What is the Digoxin nmol/L → ng/mL?
This converter turns a serum digoxin concentration from nmol/L, used by some SI-reporting laboratories and parts of the literature, into ng/mL (identical to µg/L), the unit most laboratories and guidelines use. It divides by 1.281 (equivalent to multiplying by about 0.7806), derived from the molar mass of digoxin, 780.9 g/mol.
When to use it
- Reading a digoxin level in nmol/L from an SI-reporting letter or study
- Comparing a result with a target or toxicity statement written in ng/mL or µg/L
- Continuing therapeutic drug monitoring after a patient moves between laboratories
When not to use it
- Digitoxin results — a different drug with a different molar mass
- Samples drawn during the distribution phase, which cannot be interpreted regardless of unit
- Interpreting the value: target ranges depend on the indication, the guideline and the clinical context
How it is calculated
Digoxin (ng/mL) = digoxin (nmol/L) ÷ 1.281
Clinical pearls and limitations
- Converts units only; reference ranges depend on the laboratory, the assay and the patient.
- Dividing by 1.281 is the same as multiplying by 0.7806; the ng/mL value is roughly three quarters of the nmol/L value.
- The sampling time relative to the last dose should be recorded with every level; without it the number is hard to use.
- Free digoxin assays are needed to monitor after antibody fragment treatment, because routine immunoassays measure fragment-bound drug as well.
- Amiodarone, verapamil, some macrolides and other P-glycoprotein inhibitors can raise digoxin levels; a new interaction is a common reason for an unexpected rise.
Frequently asked questions
How do I convert digoxin from nmol/L to ng/mL?
Divide by 1.281. For example, 1.9 nmol/L ÷ 1.281 = 1.48 ng/mL.
What is 1 nmol/L digoxin in ng/mL?
1 nmol/L is 0.78 ng/mL (1 ÷ 1.281 = 0.7806).
Why is the timing of a digoxin sample so important?
Digoxin distributes slowly from blood into tissue. A sample taken before distribution is complete overestimates the concentration at the site of action, so most monitoring advice asks for a sample after the distribution phase and at steady state.
Evidence and guidelines
Have a follow-up question?
Medelix answers clinical questions from current guidelines and studies — every statement with its source.
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<p><a href="https://medelix.ai/en/calculators/digoxin-nmol-l-to-ng-ml">Digoxin nmol/L → ng/mL calculator by Medelix</a></p>For healthcare professionals and medical students. These tools support, and do not replace, clinical judgement. Always check results against the original source and your local protocols.