It is an injectable drug for cardiological use, a synthetic catecholamine, direct action, with activity in alpha and beta-adrenoceptors.
Its main effect is cardiotonic and is frequently used after open-heart surgery or myocardial infarction.
Its effect is similar to the products 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 stimulating 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 produced by the onset of organic heart disease or the practice of surgical procedures of type cardiac.
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.
Dobutamine is indicated after cardiomyopathies, cardiac surgery, and cardiogenic or septic shock.
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.
For pediatric patients and 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 treatment application very safe and effective.
Dobutamine hydrochloride is contraindicated in patients with idiopathic hypertrophy, subaortic stenosis, and patients with previous hypersensitivity to dobutamine or sulfites since some presentations contain sodium metabisulfite or even any component of the formulation.
Side effects of dobutamine
- Increase in heart rate, blood pressure, and ventricular ectopic activity
In most 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 kept.
About 5% of patients have had early ventricular beats increased during infusions. These effects are related to the applied dose.
Dizzying decreases in blood pressure have occasionally been reported associated with dobutamine therapy.
Decreasing the dose or suspension of treatment generally results in a rapid blood pressure return to baseline.
However, reversibility may not be immediate on rare occasions, or intervention may be required.
- 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.
- 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.
Dobutamine can produce arrhythmias and tachycardia as adverse reactions.