Dopamine

General characteristics. Structure:

Active ingredient: 5 g or 40 g of a dopamine of a hydrochloride.           

Excipients: sodium metabisulphite, Acidum hydrochloricum of 0,1 M solution, water for injections.

Cardiotonic, hypertensive, vasodilating, diuretic means.

Pharmacological properties:

Pharmacodynamics. Excites beta adrenoceptors (in small and medium doses) and alpha adrenoceptors (in high doses). Improvement of a system hemodynamics results in diuretic effect. Exerts the specific stimulating impact on postsynaptic dopamine receptors in smooth muscles of vessels and kidneys.

In low doses (0,5-3 mkg/kg/min.) affects preferential dopamine receptors, causing expansion of renal, mezenterialny, coronary and brain vessels. Vasodilatation of kidneys leads to strengthening of a renal blood-groove, increase in a glomerular filtration rate, increase in a diuresis and removal of sodium; there is also an expansion of mezenterialny vessels (effect of dopamine on renal and mezenterialny vessels differs in it from action of other catecholamines). Stimulates postsynaptic beta1-adrenoceptors in low and average doses (2-10 mkg/kg/min.) that causes positive inotropic эффкт and increase in the minute volume of blood (MVB).

The systolic arterial pressure (AP) and pulse pressure can increase; thus diastolic the ABP does not change or slightly increases. The General Peripheric Resistance of Vessels (GPRV) usually does not change. The coronary blood stream and consumption of oxygen a myocardium, as a rule, increase.

In high doses (10 mkg/kg/min. or more) stimulation of alfa1-adrenoceptors prevails, causing increase in OPSS, the heart rate (HR) and narrowing of renal vessels (the last can reduce earlier increased renal blood stream and a diuresis). Owing to increase in the IOC and OPSS the ABP increases both systolic, and diastolic. The beginning of therapeutic effect - within 5 min. against the background of in/in introductions also proceeds within 10 min.

Pharmacokinetics. It is entered only in / century. About 25% of a dose are taken neurosecretory vesicles where there is a hydroxylation and Norepinephrinum is formed. It is widely distributed in an organism, partially passes through a blood-brain barrier (GEB). The explicit volume of distribution (newborn) – 1,8 l/kg. Communication with proteins of plasma – 50%.

It is quickly metabolized in a liver, kidneys and plasma to inactive metabolites. An elimination half-life of drug (T1/2) - adults: from plasma - 2 min., from fabrics - 9 min.; newborn – 6,9 min. (within 5-11 min.). It is removed by kidneys; 80% of a dose - in the form of metabolites during 24 h, in insignificant quantities - in not changed look.

Indications to use:

Depressed cases: cardiogenic shock; after recovery of the volume of the circulating blood (VCB) - a postoperative, hypovolemic, infectious and toxic and acute anaphylaxis; acute cardiovascular insufficiency, a syndrome of "the low IOC" at cardiac patients, arterial hypotension.

Route of administration and doses:

Enter intravenously, kapelno. The dose is established individually, depending on severity of shock, size ABP and reaction of the patient to treatment. For strengthening of a diuresis and receiving an inotropic effect (increase in sokratitelny activity of a myocardium) enter with a speed of 100 - 250 mkg/min. (1,5-3,5 mkg/kg/min.) (area of low doses). At intensive surgical care - 300-700 mkg/min. (4-10 mkg/kg/min.) (area of average doses); at septic shock - 750-1500 mkg/min. (10,5-21 mkg/kg/min.) (area of the maximum doses).

For the purpose of impact on the ABP increase in a dose to 500 mkg/min. and more is recommended, or at a constant dose of a dopamine Norepinephrinum (noradrenaline) in a dose of 5 mkg/min. weighing patient about 70 kg is in addition appointed. At emergence of disturbances of a cordial rhythm, irrespective of the applied doses, further increase in a dose is contraindicated.

To children enter 4 - 6 (at most 10) mkg/kg/min. in a dose. In difference from adults, at children the dose should be raised gradually, i.e. since the smallest dose.

Rate of administering should be selected individually for achievement of optimum reaction of the patient. At most of patients it is possible to maintain satisfactory condition at use of doses of a dopamine less than 20 mkg/kg/min.

Use duration: duration of injections depends on specific features of the patient. There is a positive experience of infusion lasting up to 28 days. After stabilization of a clinical situation drug withdrawal is made gradually.

Rule of preparation of solution: for cultivation use 0,9% solution of sodium of chloride, 5% glucose solution, solution Ringer - a lactate. To prepare solution for to infusions of 400-800 mg of a dopamine it is necessary to add to 250 ml of solvent (concentration of a dopamine will be 1,6-3,2 mg/ml). Preparation of infusion solution should be made just before use (stability of solution remains 24 h, except for mix with solution Ringer - a lactate - at most 6 h). Solution of a dopamine has to be transparent and colourless.

Features of use:

Use at pregnancy and in the period of a lactation. At pregnant women it is necessary to use drug only if the estimated advantage for mother exceeds potential risk for a fruit (in an experiment adverse action on a fruit is revealed) and/or the child. Whether Dopamin gets into breast milk it is unknown.

Before introduction by the patient who is in state of shock, the hypovolemia has to be a skorregirovana administration of plasma, etc. blood-substituting liquids.

Infusion has to be carried out under control of a diuresis, the IOC, ChSS, the ABP, an ECG. Reduction of a diuresis without the accompanying decrease in the ABP indicates the need of reduction of a dose of a dopamine.

Monoamine oxidase inhibitors (MAO), increasing pressor effect of sympathomimetics, can cause developing of headaches, arrhythmias, vomitings, etc. displays of hypertensive crisis therefore at the patients receiving MAO inhibitors during the last 2-3 weeks, initial doses of a dopamine have to make no more than 10% of a usual dose.

Strictly controlled drug use studies at patients aged up to 18 years are not conducted (this group of patients of arrhythmias and the gangrene connected with a drug ekstravazation at in introduction has separate messages on emergence).

For decrease in risk of an ekstravazation whenever possible it is necessary to enter into large veins. For prevention of a necrosis of fabrics in case of ekstravazalny hit of drug it is necessary to carry out immediately infiltration of 10-15 ml of 0,9% by chloride sodium solution from 5-10 mg of phentolamine.

Purpose of drug against the background of occlusal diseases of peripheral vessels and/or the IDCS (DVS-dessiminirovanny intravascular coagulation) in the anamnesis can cause the sharp and expressed vasoconstriction leading to a necrosis of skin and gangrene (it is necessary to carry out careful monitoring, and at detection of symptoms of peripheral ischemia drug immediately to stop introduction).

Side effects:

From outside warmly - vascular system: less often - stenocardia, tachycardia or bradycardia, heartbeat, pains behind a breast, increase or decrease in the ABP, conductivity disturbance, expansion of the QRS complex (QRS-the first phase of a ventricular complex reflecting process of depolarization of ventricles), a vasospasm, increase in end diastolic pressure in a left ventricle; at use in high doses - ventricular or supraventricular arrhythmias.

From the alimentary system: more often - nausea, vomiting, bleedings from digestive tract.

From a nervous system: more often - a headache; less often - uneasiness, motive concern, a tremor of fingers of hands.

Allergic reactions: at patients with bronchial asthma - a bronchospasm, shock.

Others: less often - an asthma, an azotemia, a piloerektion, it is rare - a polyuria (at introduction in low doses).

Local reactions: at hit of drug under skin - necroses of skin, hypodermic cellulose.

Interaction with other medicines:

Pharmaceutical it is incompatible with alkaline solutions (inactivate a dopamine), oxidizers, iron salts, thiamin (promotes B1 vitamin destruction).

The sympathomimetic effect is strengthened by adrenostimulyator, MAO inhibitors (including furasolidone, Procarbazinum, селегилин), гуанетидин (increase in duration and strengthening of the cardiostimulating and pressor effects); diuretic - diuretics; cardiotoxic effect - inhalation medicines for the general anesthesia, derivatives of hydrocarbons - such as cyclopropane, chloroform, энфлуран, a halothane, изофлуран, метоксифлуран (increase in risk of heavy atrial or ventricular arrhythmias), tricyclic antidepressants, including Maprotilinum (risk of development of disturbances of a cordial rhythm, heavy hypertensia or a hyper pyrexia), cocaine, other sympathomimetics; weaken - phenyl propyl ketones and beta adrenoblockers (propranolol).

Weakens hypotensive effect of a guanadrel, guanetidin, mekamilamin, Methyldopums, Rauwolfia alkaloids (the last prolong effect of a dopamine).

At simultaneous use with a levodopa - increase in probability of development of arrhythmias; with hormones of a thyroid gland - strengthening of action both a dopamine, and hormones of a thyroid gland is possible.

Ergometrine, ergotamine, methylergometrine, oxytocin increase vasopressor effect and risk of developing of ischemia and gangrene, and also heavy arterial hypertension, up to intracraneal hemorrhage.

Phenytoinum can promote development of arterial hypotension and bradycardia (depends on a dose and rate of administering); ergot alkaloids - to vasoconstriction and a gangrenosis.

Let's combine with cardiac glycosides (possibly increase in risk of arrhythmias of heart, the additive inotropic effect, control of an ECG is required).

Reduces anti-anginal effect of nitrates which in turn can reduce pressor effect of sympathomimetics and increase risk of developing of arterial hypotension (simultaneous use is allowed depending on achievement of necessary therapeutic effect).

Contraindications:

Hypersensitivity to drug (including to other sympathomimetics), an idiomatic hypertrophic subaortal stenosis, a thyrotoxicosis, a pheochromocytoma, closed-angle glaucoma, a benign hyperplasia of a prostate with clinical manifestations, a tachyarrhythmia, fibrillation of ventricles.

It is not necessary to appoint at arrhythmia in combination with monoaminooxidase inhibitors, with cyclopropane and galogensoderzhashy means for наркозаС care.

Hypovolemia, the expressed stenosis of the mouth of an aorta, myocardial infarction, disturbances of a heart rhythm (a tachyarrhythmia, ventricular arrhythmias, fibrillation of auricles), a metabolic acidosis, a hypercapnia, a hypoxia, hypertensia in a "small" circle of blood circulation, occlusal diseases of vessels (including atherosclerosis, a thrombembolia, an obliterating thromboangitis, an obliterating endarteritis, a diabetic endarteritis, a Raynaud's disease, freezing injury), a diabetes mellitus, bronchial asthma (if in the anamnesis hypersensitivity to disulphite was noted), pregnancy, the lactation period, age up to 18 years.

Overdose:

Symptoms: excessive increase in the ABP, spasm of peripheral arteries, tachycardia, ventricular premature ventricular contraction, stenocardia, диспноэ, headache, psychomotor excitement.

Treatment: in connection with bystry removal of a dopamine from an organism the specified phenomena are stopped at reduction of a dose or the termination of introduction, at inefficiency - alpha adrenoblockers of short action (at excessive increase in the ABP) and beta adrenoblockers (at disturbances of a rhythm).

Storage conditions:

Period of validity 3 years. Not to use after the expiry date specified on packaging. List B. In the dry, protected from light place at a temperature not above 25 °C. In the place, unavailable to children.

Issue conditions:

According to the recipe

Packaging:

5 mg/ml, 10 mg/ml, 20 mg/ml or 40 mg/ml a concentrate for preparation of solution for intravenous administration in ampoules of neutral glass on 5 ml. On 10 ampoules place in a box from a cardboard. On 5, 10 ampoules in a pack from a cardboard with partitions or lattices, or a separator of their cardboard or paper bag. On 5 ampoules place in a blister strip packaging from a film polyvinyl chloride without covering. On 1 or 2 blister strip packagings in a pack from a cardboard. Put the application instruction, a knife in each pack or a box ampoule or the scarificator ampoule ceramic (when using ampoules with notches, points or rings the knife ampoule or the scarificator is not put).