Dobutamine

Pharmacological properties

Dobutamine (1,2-benzodiol, 4- [2 - [[3- (4-hydroxyphenyl) -1-methylpropyl] amino] ethyl] -hydrochloride (±) - (±) –1,2-benzodiol, 4- [ 2 - [[3- (p-hydroxyphenyl) -1-methylpropyl] amino] ethyl] pyrocatechol) is a direct-acting inotropic agent whose activity is due to selective stimulation of β1-adrenergic receptors and α1-adrenergic receptors of the heart. dobutamine causes dose-dependent changes in hemodynamics: it increases cardiac output, mainly due to an increase in stroke volume of the blood, increases heart rate (less pronounced than catecholamines), reduces the filling pressure of the left ventricle, systemic vascular resistance, and when used in high doses, also reduces the resistance of pulmonary vessels; increases av-conductivity and automatism of the sinus node; reversibly inhibits platelet aggregation, increases myocardial oxygen demand (increased mok and, as a result, increased coronary blood flow, as a rule, compensates for this effect and determines the tendency to a more favorable oxygen balance compared to other positive inotropic drugs); does not affect dopaminergic receptors and, unlike dopamine, on the release of endogenous epinephrine; does not have a direct dopaminergic effect on kidney perfusion; may cause arrhythmias.

In heart failure with concomitant acute or chronic myocardial ischemia, dobutamine is recommended in doses that do not cause a significant increase in heart rate and blood pressure, since otherwise the progression of ischemia cannot be ruled out.

Tolerance to the drug may occur after continuous administration for 72 hours, possibly due to a decrease in the activity of the adenylate cyclase system.

The action of the drug begins 1-2 minutes after the start of the infusion, but a constant level of dobutamine in the blood plasma with continuous administration is achieved only after 10-12 minutes. An increase in plasma dobutamine levels is linear with respect to dose and rate of administration. The elimination half-life makes 2-3 minutes.

Dobutamine is metabolized primarily in the tissues and liver with the formation of conjugated glucuronides and pharmacologically inactive 3-O-methyldobutamine and excreted mainly in the urine.

Indications

It is used as a cardiotonic agent in the treatment of patients with heart failure with low cardiac output due to myocardial infarction, cardiomyopathy, infectious allergic shock, cardiogenic shock and heart surgery.

Application

The dose of dobutamine is set individually. the speed and duration of administration of the drug depends on the patients response to treatment and the appearance of side effects. in cases of continuous administration for more than 72 hours, tolerance to the drug may develop and, therefore, a need to increase the dose may appear.

Before stopping the administration of the drug, it is recommended to reduce the dose gradually.

For most adults, administration at a rate of 2.5–10 mcg / kg / 1 min is sufficient.

In some cases, the dose of dobutamine can reach 40 mcg / kg / min.

Dobutamine can be used in children of any age. It is recommended to start administration at a rate of 2.5–5 μg / kg / min, gradually increasing it to a maximum (20 μg / kg / min) depending on the effect.

Caution should be exercised when prescribing a high dose of the drug to children. Most side effects, especially tachycardia, are noted with the use of dobutamine in children in doses exceeding 7.5 μg / kg / min.

Dobutamine Solway in 50 ml of solution for infusions (1 ampoule) can be used undiluted when using infusion pumps. If necessary, the drug before administration can be further diluted in 5% glucose solution, isotonic solution or Ringers lactate solution.

The drug can be prescribed only in the form of iv infusions.Since dobutamine has a short half-life, the administration of the drug should be continuous. To ensure dosing accuracy, dobutamine solutions in high concentration should be prescribed only through an infusion pump.

The tables show the rate of administration of dobutamine for different concentrations of solution.

Dosing when using infusion pumps (1 ampoule contains 250 mg of dobutamine per 50 ml of solution)

Dosing when using infusion systems (1 bottle contains 250 mg of dobutamine per 500 ml of solution)

* When using a solution of double concentration, the rate of administration must be reduced by half.

Contraindications

Hypersensitivity to dobutamine, mechanically difficult filling