Dobutamine: What Is It For?

Dobutamine is a drug with positive inotropic effects that is therefore used for the treatment of heart failure and cardiogenic shock. It is given intravenously.

Although dobutamine is structurally similar to dopamine and other catecholamines, this drug is a synthetic compound analogous to isopreterenol and has different pharmacological properties, including the aforementioned inotropism, chronotropism and vasodilation.

Unlike dopamine, dobutamine does not affect dopamine receptors , although urine output may increase due to increased cardiac output, for example.

Inotropism and chronotropism?

The circulatory system has a series of fundamental functions for the correct functioning of the body. Among the most important we can mention the following:

• Transporting and distributing essential substances to tissues .
• Remove metabolic waste.
• Adjust the supply of oxygen and nutrients in different physiological states.
• Regulation of body temperature.
• Humoral communication .

The heart has a series of characteristics that we need to clarify in order to better understand its functioning and the mechanism of dobutamine. Among these features are:

• Automation: the heart beats automatically.
• Inotropism: the heart contracts under certain stimuli. The sympathetic nervous system has a positive inotropic effect, therefore, it increases the contractility of the heart.
• Chronotropism: refers to the slope of the action potential. The sympathetic nervous system increases the tilt, therefore, produces tachycardia. On the other hand, the parasympathetic nervous system decreases it.

• Baptmotropism: The heart can be stimulated while maintaining a threshold.
• Dromotropism: is the rate of conduction of cardiac impulses through the excito-conductive system. The sympathetic nervous system has a positive dromotropic effect, so driving speed increases. The parasympathetic nervous system has an opposite effect.
• Lusitropism: is the relaxation of the heart under certain stimuli.

Dobutamine Indications

Dobutamine is a drug that is used to treat potentially recoverable acute heart failure . Some of them are, for example, those that are triggered during heart surgery or in cases of septic shock. All these effects are justified by the characteristic inotropic action of this drug.

Dobutamine can also be used in patients suffering from congestive heart failure in order to increase the heart’s performance. It is generally used in cases where the patient requires parenteral nutrition as an inotropic support in the short-term treatment that patients with cardiac decompensation receive due to a deficiency in myocardial contractility.

On the other hand, it is important to mention that dobutamine is not used in the treatment of ischemic heart disease, because it greatly increases the heart rate , which is accompanied by the consequent myocardial oxygen demand.

How does dobutamine trigger its effect on the body?

Dobutamine interacts with beta-1-adrenergic receptors , activating them . It also has beta-2 and alpha-1 stimulant effects, but these are minor. Thus, it can increase myocardial contractility and stroke volume. In this way, a series of modest chronotropic effects are triggered, which causes an increase in cardiac output.

As a consequence of these effects, others occur at the hemodynamic level, such as a decrease in systemic vascular resistance and ventricular filling pressure. In addition, blood pressure also tends to increase due to increased stroke volume , despite the fact that diastolic pressure and the middle artery are normally maintained without changes.

As we mentioned at the beginning of the article, dobutamine has no effect on dopamine receptors , unlike this neurotransmitter. It also does not cause the release of norepinephrine from sympathetic nerve endings.

Adverse effects of dobutamine treatment

As with any other marketed drug, dobutamine is not free from side effects . There are adverse effects with its use. We understand adverse effects as all the undesirable and unintended events that are expected from treatment with a drug.

In this sense, among its adverse effects may occur:

• Ventricular dysrhythmias.
• Arterial hypertension.
• Increase in systolic frequency .
• Nausea
• Headache.
• Angina
• Difficulty breathing.

Conclusion

Dobutamine is a drug mainly indicated for the treatment of heart failure, due to its ability to increase the contractility of the heart as well as the heart rate. However, it can trigger a series of adverse effects that should be evaluated with the doctor when starting a treatment with this medicine.