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Digoxin in the serum
Last reviewed: 05.07.2025
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The concentration of digoxin in the blood serum when used in therapeutic doses is 0.8-2 ng/ml (1.2-2.7 nmol/l). The toxic concentration is more than 2 ng/ml (more than 2.7 nmol/l).
The half-life of digoxin in adults is 38 hours with normal renal function and 105 hours with anuria. The time to reach the drug's equilibrium state in the blood is 5-7 days.
Digoxin is one of the most commonly used cardiac glycosides. It is usually taken for a month. Absorption in the gastrointestinal tract is 60-80% of the dose taken. Most of the drug is excreted from the blood by the kidneys. Digoxin is prescribed mainly for heart failure and as an antiarrhythmic agent, along with other drugs. In chronic digoxin poisoning, hypokalemia is most often observed, and in acute poisoning - hyperkalemia. Most symptoms of digoxin toxicity occur at a blood concentration of 3-5 ng / ml (3.8-6.4 nmol / l). Higher concentrations, as a rule, are the result of improper blood sampling for research.
Clinical use of cardiac glycosides
Parameters |
Digoxin |
Digitoxin |
Half-life, h |
38 |
168 |
Therapeutic concentration, ng/ml |
0.8-2.0 |
14-26 |
Daily dose, mg |
0.125-0.5 |
0.05-0.2 |
Dose for fast digitalization |
0.5-0.75 mg every 8 hours, divided into 3 doses |
0.2-0.4 mg every 8 hours, divided into 3 doses |
Time to maximum concentration, h |
3-6 |
6-12 |
Rules for taking blood for research. The material for research is blood serum. It is better to take a blood sample 12-24 hours after taking the last dose of the drug. Hemolysis of blood leads to an increase in the results of the study.
Monitoring of digoxin blood concentrations should be performed in patients with the following risk factors:
- disturbances in the electrolyte composition of the blood (hypokalemia, hypomagnesemia, hypercalcemia);
- concomitant pathology (kidney disease, hypothyroidism);
- taking digoxin together with other drugs (diuretics, quinidine, β-adrenergic agonists).
Clinical signs of drug overdose include nausea, vomiting, diarrhea, anorexia, headaches, hallucinations, impaired light perception, sinus tachycardia, atrial or ventricular extrasystole, atrioventricular block.
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