Digoxin in serum

The concentration of digoxin in serum when used in therapeutic doses is 0.8-2 ng / ml( 1.2-2.7 nmol / l).Toxic concentration - more than 2 ng / ml( more than 2,7 nmol / l).

The digoxin half-life in adults is 38 hours with normal kidney function and 105 hours with anuria. The time to reach the equilibrium state of the drug 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. Of the blood, most of the drug is excreted by the kidneys. Prescribe digoxin, mainly in heart failure and as an antiarrhythmic drug, along with other drugs( Table).When chronic poisoning with digoxin is most often observed hypoka-

, and in acute poisoning - hyperkalemia. Most of the symptoms of toxic effects of digoxin occur with a blood concentration of 3-5 ng / ml( 3.8-6.4 nmol / l).Higher concentrations are usually the result of improper blood sampling for research.

Table Clinical use of cardiac glycosides [Karkishchenko NN, 1996]

Table Clinical use of cardiac glycosides [Karkishchenko NN, 1996]

Rules for blood sampling for studies. The material for the study is serum. A sample of blood is best taken 12-24 hours after the last dose of the drug. Hemolysis of blood leads to an increase in the results of the study.

Digoxin concentration in the blood should be monitored in patients who have the following risk factors:

■ electrolyte dysfunction( hypokalemia, hypomagnesium, hypercalcemia);

■ concomitant pathology( kidney disease, hypothyroidism of the thyroid gland);

■ ingestion of digoxin together with other drugs( diuretics, quinidin, b-adrenomimetics).

Clinical signs of drug overdose - nausea, vomiting, diarrhea, anorexia, headaches, hallucinations, light-impairment disorders, sinus tachycardia, atrial or ventricular extrasystole, atrioventricular block.