The pharmacological action 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 reacts to the natural hormone dopamine, which is synthesized by brain cells under normal conditions. The use of this tool in medicine is dictated by the need to effectively combat 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 a causative agent of beta and alpha type adrenoreceptors, positively affect systemic hemodynamics and qualitatively improve the functioning of the muscles of the blood highways and kidneys. The active substance is distributed throughout the body evenly, while part of the reagentscrosses the blood-brain barrier.
The therapeutic effect occurs within five minutes after the administration of the drug and lasts a total of about ten minutes. As a result of metabolism, which occurs in the liver, kidneys and partly in plasma, inactive compounds are formed. About 80% of the dose is excreted from the body in the urine as metabolites already on the first day.
When is Dopamine recommended?
Instructions for use defines the following list of cases:
- shock of various origins (including a condition resulting from an operation or a toxic infection, as well as a cardiac disorder);
- cardiovascular insufficiency (acute);
- complex or ordinary food poisoning (the drug increases diuresis, which favorably affects the rate of elimination of toxins);
- arterial hypotension.
Use and dosage of "Dopamine"
The medicine belongs to the group of intravenous drip drugs. The calculation of the dose is made taking into account the real shock situation and with a mandatory correction for blood pressure. In addition, the overall response of the patient to the infusion is taken into account.
It is important to understand that dose (mg) is not the only criterion in making a prediction. The final effect largely depends on the speed at which the Dopamine drug is administered. The instructions for use highlight the following scenarios:
- increased urination - from 100up to 250 mcg/min;
- surgical therapy - 300 to 700 mcg/min;
- cardiological crisis or dynamic septic shock - 750 to 1500 mcg/min.
If a cardiac arrhythmia was detected with the introduction of a small amount of the solution, 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 response.
Maximum doses of dopamine for the same patient may be different - the target is the target (excitation 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 mark of 30 mcg / kg / min or more, as this may adversely affect the patient's condition.
Contraindications to "Dopamine"
About cases when the use of the drug is contraindicated, informs all the same instructions for use. "Dopamine", in particular, is not prescribed to patients who have been diagnosed with a complex pathology of the thyroid gland or have chronic ailments that affect the work of the adrenal glands. Of course, individual intolerance to the components of the drug should also become a limitation.
Impaired heart rhythm in a patient or progressive atherosclerosis are two more rather serious factors that can form the basis of a doctor's reasoned position regarding the non-use of an infusion solution. In addition, it is highly undesirable to resort tosetting droppers with "Dopamine", if the following diagnoses occur:
- thyrotoxicosis;
- diabetes mellitus;
- pheochromocytoma.
It is impossible to allow the simultaneous administration of the drug with anesthetics made on the basis of a halogen (or its derivatives). The attending physician decides on the appointment of a medication for pregnant women.
Side effects: symptoms and nature of the course
The drug "Dopamine" (instruction 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 qualified 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 varying intensity in the chest area, etc.). Other allergic reactions include bronchial spasms, nausea, severe headaches, agitation alternating with 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 supposed optimal norm (mg) in small quantities can lead to hiddenprocesses that are difficult to diagnose, which complicates the neutralization of the likely negative consequences of intravenous administration of Dopamine.
Special Instructions
The specific mechanism of reactions determines additional conditions for the use of the drug "Dopamine". Instructions for use reads:
- prior to the administration of the solution to a patient in shock, it is necessary to correct hypovolemia by injecting a blood-substituting fluid;
- Patients who have regularly received monoamine oxidase inhibitors in recent weeks are prescribed no more than 10% of the usual dose;
- infusion should be accompanied by mandatory control of the rate of urination and periodicity of heart contractions; blood pressure should also be monitored (a stable load on the blood vessels with a noticeable decrease in diuresis is a signal that the dose of Dopamine needs to be reduced);
- patients under 18 automatically fall into the risk group, since for this age group no large-scale studies have been conducted regarding the reaction of organs and systems to the components of the drug;
- the introduction of the solution into the body, if possible, should be carried out through large blood lines (to minimize the risk of extravasation); if the release of blood from the vessels into the tissues nevertheless occurred, 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 onFrom the features of the chemical structure of the drug "Dopamine" (the description of the drug is given above), we can conclude that it is pharmaceutically compatible. In particular, the solution does not react well to alkaline liquids (deactivation of the components occurs), as well as to iron s alts and thiamine (the latter breaks down vitamin B1 molecules). The hypotensive effect of the infusion fades if mecamylamine (or its derivatives) is involved in the therapeutic course in parallel with "Dopamine".
Synchronous use of the drug with levodopa almost guarantees the occurrence of a progressive arrhythmia. In turn, active substances such as ergometrine and ergotamine can cause gangrene, and in conditions of a critical overdose of Dopamine, even cause intracranial hemorrhage.
Good compatibility with glycosides used in cardiology and diuretics.
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 reflects the degree of their availability on the domestic market):
- "Dopamine", country of origin - Russia.
- Dopamine-Admeda, Germany.
- Dopamine-Solvay 200, Germany.
- Dopamine-Solvay 50, Germany.
- Dopamine Hydrochloride, Poland.
- Dopmin, Finland.
"Dopamine": opinions and comments
Due to the specifics of the actiondrug, it is almost impossible to get acquainted with the opinion of patients regarding its effectiveness (patients undergo an infusion procedure while in a state of shock, while in intensive care or directly on the operating table). Professional controversy, deployed on the pages of the forums, is conducted mainly by anesthesiologists 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 drug with a non-conservative mechanism of action: the course of the reaction is controlled from the moment the primary dose is administered until the desired result is achieved, that is, throughout the entire length of the time period. Moreover, the doctor, by adjusting the volume and speed of the solution through the dropper, can change the vector of its medicinal properties.
The natural hormone dopamine and its antagonists
The informal name for dopamine is the flight hormone. This complex chemical compound is synthesized by brain cells and ensures the normal (familiar in human understanding) work of all muscle groups and not only. Bliss, lightness, readiness for any trials - this is how the psychophysical portrait of an individual looks like, in whose body this hormone has been released. With a shortage of a substance, a “crisis of pleasure” sets in: detachment is visible in behavior, unwillingness to accept what is happening around, movements are constrained, thought processes are inhibited.
Sometimesthere is a need for artificial blocking of receptors that respond to the flight hormone. The role of an insurmountable barrier is performed by dopamine antagonists. Medicines of this group exclude the possibility of obtaining "natural satisfaction", that is, in fact, they extinguish the patient's psychophysical activity. Prescription prescription of antagonists of this hormone is justified in schizophrenia, treatment of drug addiction, chronic migraines, indigestion.
