Dobutamine: Chemical Formula, Mechanism of Action, Indications, Dosage, Side Effects, Precautions and Contraindications

It is an injectable drug for cardiological use, a synthetic catecholamine, direct action, with activity in alpha and beta adrenoceptors.

Its main effect is as cardiotonic and is frequently used after open heart surgery or myocardial infarction .

Its effect is similar to the effects produced in the body by intense physical activity.

Dobutamine is a direct action inotropic agent, the primary activity is not more than the result of the stimulation of the beta – adrenoceptors of the heart while producing hypertensive, arrhythmogenic chronotropic and comparatively mild vasodilator effects.

The dobutamine operates on β-1 adrenergic receptors, with little effect on β-2 or α receptors.

This compound causes the release of endogenous norepinephrine, in the same way as dopamine, and is recommended when parenteral therapy in cases of depressed contractility that is produced by the onset of an organic heart disease or the practice of surgical procedures of type cardiac

Chemical formula

C18H23NO3

1,2-benzenediol, 4- [2 – [[3- (4-hydro-xyphenyl) -1-methylpropyl] amino] ethyl] -hydrochloride

Mechanism of action

Dobutamine directly stimulates the Beta-1 receptors in the heart to increase myocardial contractility and stroke volume, which translates into an increase in cardiac output.

The clinical hemodynamic purpose of dobutamine is to increase the contractility of the myocardium, so that as a response to the increase in stroke volume, there is a reduction in systemic vascular resistance, without significant changes in blood pressure or heart rate.

In the state of acute heart failure with high afterload pressures, which are derived from myocardial dysfunction, dobutamine therapy is still the most used.

Indications

Dobutamine is indicated after cardiomyopathies, cardiac surgery and in cardiogenic or septic shock.

Dose

Adults:

The dose used to which response has been observed in patients is 2.5-10 micrograms of dobutamine / kg / min.

On rare occasions, doses of up to 40 micrograms of dobutamine / kg / min are administered to obtain the desired effect.

Children:

For pediatric patients, newborns up to 18 years of age, an initial dose of 5 micrograms / kg / minute is recommended, adjusted according to the clinical response to 2- 20 micrograms / kg / minute.

Precautions and contraindications

During the administration of the dobutamine injection, as with any adrenergic agent, the electrocardiogram (ECG) and blood pressure should be continuously monitored.

Also, pulmonary pressure and cardiac output should be reviewed whenever possible to help make the application of the treatment very safe and effective.

Dobutamine hydrochloride is contraindicated in patients with idiopathic hypertrophy, subaortic stenosis and in patients who have shown previous manifestations of hypersensitivity to dobutamine or sulfites since some presentations contain sodium metabisulfate, or even any component of the formulation.

Side effects of dobutamine

1. Increase in heart rate, blood pressure and ventricular ectopic activity

In the majority of patients treated with dobutamine, an increase in heart rate of 5 to 15 beats / minute has been observed, and systolic blood pressure of 10 to 20 mm has been observed.

About 5% of patients have had early ventricular beats increased during infusions. These effects are related to the applied dose.

2. Hypotension

Dizzying decreases in blood pressure have occasionally been reported in association with dobutamine therapy.

Decreasing the dose or suspension of treatment generally results in a rapid return of blood pressure to baseline.

However, on rare occasions, reversibility may not be immediate or intervention may be required.

3. Reactions in the sites of intravenous application

Local inflammatory changes have occurred after an application.

Phlebitis has been reported occasionally.

Isolated cases of skin necrosis (destruction of skin tissue) have been reported.

Also, isolated cases of thrombocytopenia have been reported.

4. Other unusual effects

Adverse effects have been reported in 1% to 3% of patients, such as headache, anginal pain, nonspecific chest pain, nausea, palpitations and sometimes difficulty breathing.

The administration of dobutamine, like other catecholamines, can cause a slight decrease in the serum concentration of potassium, but very occasionally at hypokalemic levels.

Adverse reactions

Dobutamine can produce arrhythmias and tachycardia as adverse reactions.

Dobutamine may increase myocardial ischemia in susceptible patients, due to its effect on the increase in heart rate and contractility.