The pharmacological effect of the drug “Dopamine” is due to its belonging to adrenergic substances and is reduced to a general increase in tone, stimulation of the heart muscle and blood vessels, activation of processes occurring in the central nervous system. Similarly, the body responds to the natural hormone dopamine, which under normal conditions is synthesized by brain cells. The use of this drug in medicine is dictated by the need to effectively deal with the consequences of shock conditions, cardiovascular diseases (including arrhythmia), food poisoning and depression.
Metabolism and Kinetics
According to the instructions for use, Dopamine, depending on the dosage, can act as the causative agent of beta and alpha type adrenergic receptors, positively affect systemic hemodynamics and qualitatively improve the functioning of the muscles of the blood lines and kidneys. The active substance spreads throughout the body evenly, while part of the reagents overcomes the blood-brain barrier.
The therapeutic effect occurs within five minutes after administration of the drug and lasts a total of about ten minutes. According to the results of metabolism, which occurs in the liver, kidneys and partially in the plasma, inactive compounds are formed. About 80% of the dose is excreted in the urine in the form of metabolites in the first day.
When is Dopamine recommended?
Instructions for use determine the following list of cases:
- shock of various origins (including a condition resulting from a surgery or toxic infection, as well as a cardiological disorder);
- cardiovascular failure (acute form);
- complex or conventional food poisoning (medication enhances diuresis, which favorably affects the rate of toxin elimination);
- arterial hypotension.
The use and dosage of "Dopamine"
The medicine belongs to the group of intravenous drip. The dose is calculated taking into account the real shock situation and with the obligatory correction for blood pressure. In addition, the patient's response to the infusion as a whole is taken into account.
It is important to understand that the dose (mg) is not the only criterion in making a forecast. The final effect largely depends on how fast the drug “Dopamine” is administered. Instructions for use identifies such scenarios:
- increased urination - from 100 to 250 mcg / min;
- therapy associated with surgical interventions - from 300 to 700 mcg / min;
- cardiological crisis or dynamic shock of a septic nature - from 750 to 1500 mcg / min.
In the event that with the introduction of a small amount of the solution, cardiac arrhythmia was detected, the dose is not increased. For pediatric patients, the drug is instilled with an intensity of 4 to 6 μg / kg / min. The speed is selected individually, based on the conditions for achieving the optimal reaction.
The maximum doses of dopamine for the same patient may be different - the goal is the goal (stimulation of the muscles of the kidneys, blood vessels, heart, etc.). But it is not recommended to increase the intensity of the drug supply to the level of 30 mcg / kg / min or more, since this can negatively affect the patient's condition.
Contraindications to "Dopamine"
About cases where the use of the drug is contraindicated, all the same instructions for use informs. "Dopamine", in particular, is not prescribed to patients who are diagnosed with a complex thyroid pathology or have chronic ailments that affect the work of the adrenal glands. Of course, individual intolerance to the components of the drug should also be a limitation.
Violation of the patient’s heart rhythm or progressive atherosclerosis are two other rather serious factors that can underlie the physician’s reasoned position regarding the non-use of the infusion solution. In addition, it is extremely undesirable to resort to the establishment of droppers with "Dopamine", if the following diagnoses occur:
- thyrotoxicosis;
- diabetes;
- pheochromocytoma.
The simultaneous administration of the drug with anesthetics made on the basis of halogen (or its derivatives) cannot be allowed. The appointment of the medication to pregnant women is decided by the attending physician.
Side effects: symptoms and nature of the course
The drug "Dopamine" (instructions for use directly indicates this) is a multifunctional tool for influencing the human body. Moreover, the conditional line between the beneficial effect and the scenario, when the infusion provokes the development of side effects, is so thin that the very fact of using the drug can be described as the prerogative of experienced and highly skilled specialists.
So, for example, unsuccessful attempts to stimulate the cardiovascular system turn into point or complex cataclysms (there are sharp jumps in blood pressure, sharp pains of different intensities in the region of the chest, etc.). Among other allergic reactions are bronchial cramps, nausea, severe headaches, an excited state, followed by causeless anxiety, shortness of breath.
Sometimes there are small skin necrosis, nose and stomach bleeding. With a severe overdose, identification of side effects is not difficult. However, exceeding the expected optimal norm (mg) in small amounts can result in latent processes that are difficult to diagnose, which complicates the neutralization of the likely negative consequences of the intravenous administration of Dopamine.
special instructions
A specific reaction mechanism determines additional conditions for the use of the drug “Dopamine”. Instructions for use read as follows:
- before the solution is administered to a patient in a state of shock, it is necessary to correct hypovolemia due to the injection of blood-replacing fluid;
- patients who regularly received monoamine oxidase inhibitors over the past weeks are prescribed no more than 10% of the usual dose;
- infusion should be accompanied by mandatory monitoring of the rate of urination and the periodicity of heart contractions; blood pressure should also be monitored (stable load on the blood vessels with a marked decrease in diuresis - a signal that the dose of “Dopamine” needs to be reduced);
- patients under 18 years old automatically fall into the risk group, since for this age category no large-scale studies have been conducted regarding the response of organs and systems to the components of the drug;
- whenever possible, the introduction of the solution into the body should be carried out through large blood lines (to minimize the risks of extravasation); if the exit of blood from the vessels into the tissue did occur, it is necessary to take measures for immediate infiltration;
- at the first suspicion of the development of peripheral ischemia, the use of the drug is stopped.
Interaction with other medicines
Based on the characteristics of the chemical structure of the drug "Dopamine" (the description of the drug is given above), we can conclude its pharmaceutical compatibility. In particular, the solution does not respond well to alkaline liquids (components are deactivated), as well as to iron salts and thiamine (the latter breaks down the molecules of vitamin B1). The antihypertensive effect of the infusion fades if mecamylamine (or its derivatives) is involved in the therapeutic course in parallel with Dopamine.
The simultaneous use of the drug with levodopa practically guarantees the occurrence of progressive arrhythmias. In turn, such active substances as ergometrine and ergotamine can cause gangrene, and in the event of a critical overdose of Dopamine, they can even cause intracranial hemorrhage.
Good compatibility with glycosides used in cardiology and diuretics is noted.
Popular analogues of "Dopamine"
Trade names of drugs, the active formula of which corresponds to the structure of the drug “Dopamine” (analogues are presented in the order that displays the degree of their availability in the domestic market):
- Dopamine, manufacturing country - Russia.
- "Dopamine-Admeda", Germany.
- "Dopamine-Solway 200", Germany.
- "Dopamine-Solway 50", Germany.
- Dopamine Hydrochloride, Poland.
- Dopmin, Finland.
Dopamine: Opinions and Comments
Due to the specificity of the drug’s action, it’s almost impossible to get an opinion of patients regarding its effectiveness (patients undergo an infusion procedure while in a state of shock, being in intensive care or directly on the operating table). Professional polemics deployed on the pages of forums are mainly conducted by anesthetists and employees of the ambulance service.
“Dopamine”, reviews of which for the most part will be incomprehensible to a person without an appropriate education, is a medication with a non-conservative mechanism of action: the course of the reaction is controlled from the moment the initial dose is administered until the desired result is achieved, that is, over the entire length of time. Moreover, the doctor by adjusting the volume and speed of the solution through the dropper can change the vector of its healing properties.
Natural hormone dopamine and its antagonists
The unofficial name for dopamine sounds like flight hormone. This complex chemical compound is synthesized by brain cells and provides normal (familiar to the human understanding) work of all muscle groups and not only. Bliss, lightness, readiness for any tests - this is how the psychophysical portrait of the individual looks like in the body of which the release of this hormone occurred. With a deficiency of substance, a “crisis of pleasure” sets in: behavior detaches itself, reluctance to accept what is happening around it, the movements are constrained, mental processes are inhibited.
Sometimes there is a need for artificial blocking of hormone-responsive receptors. The role of an insurmountable barrier is played by dopamine antagonists. Medicines of this group exclude the possibility of obtaining "natural satisfaction", that is, in fact, quench the psychophysical activity of the patient. The prescription of antagonists of this hormone is justified in schizophrenia, drug dependence treatment, chronic migraines, and indigestion.