Description of the drug
The drug is medically called magnesium sulfate. This drug is often used by specialists as a first aid treatment for high blood pressure. Magnesia is one of the drugs that can be used to obtain an immediate effect and normalize the patient’s condition.
Currently, this drug is produced by manufacturers in several forms. The pharmacy chain offers the following forms of the drug:
- 25% solution - ampoules, in a package of 10 pcs.;
- Powder - free-flowing consistency in packaging of various weights;
- Tablets - in packs of 200 pcs.
Magnesium sulfate is used in the form of a solution to normalize blood pressure. It also contains B vitamins.
How does magnesium affect blood pressure?
The beneficial effect on the well-being of a patient with high blood pressure is due to the magnesium content of the drug. This element in the human body is necessary for the normal functioning of the nervous system.
The drug helps increase magnesium content and has the following effects on high blood pressure.
- diuretic;
- anticonvulsant;
- soothing;
- normalization of heart rate;
- vasodilator.
After the active substance enters the bloodstream, the coronary vessels dilate due to the release of contractions, which lowers blood pressure and normalizes cardiovascular function.
By changing the administered dose of the drug, you can get a sedative or narcotic effect.
This effect is due to the ability to suppress neuromuscular impulses.
Prehospital care for sudden increases in blood pressure and hypertensive crisis
R
a sharp sudden increase in blood pressure (BP) to individually high values with minimal subjective and objective symptoms is considered as an uncomplicated hypertensive crisis (HC), and in the presence of dangerous or violent manifestations with subjective and objective signs of cerebral, cardiovascular and autonomic disorders is called complicated GK.
According to the National Scientific and Practical Society of Emergency Medical Care, over the past 3 years in the Russian Federation as a whole, the number of emergency medical services (EMS) calls for hypertensive crisis and the number of hospitalizations has increased by an average of 1.5 times. However, to date, at the prehospital stage, there is no clear algorithm for the use of drugs to provide emergency care for a sudden increase in blood pressure or blood glucose.
A sudden increase in blood pressure can be provoked by neuropsychic trauma, alcohol consumption, sharp fluctuations in atmospheric pressure, withdrawal of antihypertensive therapy, etc. In this case, two main pathogenetic mechanisms play a major role: vascular
– increase in total peripheral resistance due to an increase in vasomotor (neurohumoral influences) and basal (with sodium retention) arteriolar tone;
and cardiac
- an increase in cardiac output due to an increase in heart rate, circulating blood volume (CBV), and myocardial contractility.
Clinically, HA is manifested by subjective and objective signs. Subjective signs include headache, non-systemic dizziness, nausea and vomiting, blurred vision, cardialgia, palpitations and interruptions in cardiac function, shortness of breath; to objective - excitement or lethargy, chills, muscle tremors, increased humidity and hyperemia of the skin, low-grade fever, transient symptoms of focal disorders in the central nervous system; tachy- or bradycardia, extrasystole; clinical and ECG signs of left ventricular hypertrophy; accent and splitting of the second tone over the aorta; signs of systolic overload of the left ventricle on the ECG.
Thus, the diagnosis of GC is based on the following main criteria
: sudden onset; individually high rise in blood pressure; the presence of cerebral, cardiac and autonomic symptoms.
The tactics of providing emergency care depend on the severity of symptoms, the height and persistence of blood pressure, in particular diastolic blood pressure, as well as the cause that caused the increase in blood pressure and the nature of complications.
Depending on the characteristics of central hemodynamics, hyper- and hypokinetic GCs are distinguished (Table 1). The most common complications of GC are presented in Table 2.
The algorithm for relieving a hypertensive crisis is presented in Figure 1. When treating a sudden increase in blood pressure that is not accompanied by a violent clinical picture and the development of complications, mandatory medical intervention is required, which, however, should not be aggressive. One should remember about the possible complications of excessive antihypertensive therapy - drug collapse and a decrease in cerebral blood flow with the development of cerebral ischemia. Blood pressure should be reduced especially gradually and carefully (by no more than 20–25% of the initial value within 40 minutes) in case of vertebrobasilar insufficiency and the appearance of focal neurological symptoms. Moreover, the patient should be in a horizontal position due to the possibility of a sharper decrease in blood pressure. In the vast majority of cases, sublingual use of medications is possible to treat a sudden increase in blood pressure.
Rice. 1. Algorithm for relieving hypertensive crisis
In the absence of significant tachycardia, it is advisable to begin therapy for an uncomplicated crisis with 10–20 mg
of nifedipine
sublingually. The drug is characterized by good predictability of the therapeutic effect: in the vast majority of cases, after 5–30 minutes, a gradual decrease in systolic and diastolic blood pressure begins (by 20–25%) and the patients’ well-being improves, which allows one to avoid the uncomfortable (and sometimes dangerous) parenteral use of antihypertensive drugs for the patient funds. The duration of action of the drug is 4–5 hours, which allows you to begin the selection of planned antihypertensive therapy at this time. If there is no effect, nifedipine can be repeated after 30 minutes. Clinical observations show that the higher the level of initial blood pressure, the higher the effectiveness of the drug. Side effects of nifedipine are associated with its vasodilating effect - drowsiness, headache, dizziness, flushing of the skin of the face and neck, tachycardia. Contraindications: Tachy-Brady syndrome (as a manifestation of sick sinus syndrome); acute coronary insufficiency (acute myocardial infarction, unstable angina); severe heart failure; hemodynamically significant stenosis of the aortic mouth; hypertrophic cardiomyopathy; hypersensitivity to nifedipine. It should be taken into account that in elderly patients the effectiveness of nifedipine increases, therefore the initial dose of the drug when treating GC should be less than in young patients.
captopril sublingually.
at a dose of 25–50 mg. When taken sublingually, the hypotensive effect of captopril develops after 10 minutes and lasts for about 1 hour. Side effects of ACE inhibitors: angioedema; allergic skin reactions; impaired renal function (in patients at risk - increased levels of urea and creatinine, proteinuria, oliguria); dry cough (due to increased bradykinin levels and increased sensitivity of bronchial receptors); bronchospasm; arterial hypotension, headache, dizziness, weakness, fatigue, fainting, palpitations. Contraindications: bilateral renal artery stenosis; condition after kidney transplantation; hemodynamically significant stenosis of the aortic mouth, left atrioventricular orifice, hypertrophic cardiomyopathy. The use of ACE inhibitors is not indicated during pregnancy, including pregnancy eclampsia.
In case of hyperkinetic variant of hypertensive crisis, sublingual administration of clonidine
at a dose of 0.075 mg. The hypotensive effect develops within 15–30 minutes, the duration of action is several hours. Side effects: dry mouth, drowsiness, orthostatic reactions. Taking clonidine is contraindicated in cases of bradycardia, sick sinus syndrome, and atrioventricular block of II–III degree; its use is undesirable in acute myocardial infarction, severe encephalopathy, obliterating diseases of the vessels of the lower extremities, and depression.
If there are contraindications to the use of beta-blockers, magnesium sulfate
at a dose of 1000–2500 mg IV slowly (over 7–10 minutes or more), and if it is impossible to provide IV administration of the drug, it is permissible (as an exception) to administer the drug warm IM followed by warming the injection site. Magnesium sulfate has a vasodilator, sedative and anticonvulsant effect, reduces cerebral edema. Its use is especially indicated for GC, accompanied by the development of convulsive syndrome (in particular, with eclampsia in pregnant women), as well as with the appearance of ventricular arrhythmias against the background of increased blood pressure. The hypotensive effect develops 15–25 minutes after administration. Side effects: respiratory depression (can be eliminated by intravenous administration of 5–10 ml of 10% calcium chloride solution), bradycardia, second degree atrioventricular block. Contraindications: hypersensitivity, hypermagnesemia (renal failure, hypothyroidism), myasthenia gravis, severe bradycardia, second degree atrioventricular block.
When treating complicated HA, a rapid (within the first minutes, hours) reduction in blood pressure by 20–30% compared to the initial level is necessary. For this purpose, parenteral administration of drugs is mainly used.
HC with hypertensive encephalopathy requires rapid and careful lowering of blood pressure
, treatment and prevention of cerebral edema and convulsive syndrome.
To do this, use nifedipine
p.o. at a dose of 10–20 mg (chew).
If its effectiveness is insufficient, as well as if it is impossible to use sublingual medication (for example, with persistent vomiting), it is advisable to use magnesium sulfate
(1000–2500 mg IV slowly over 7–10 minutes) and IV administration of dibazole. Dibazol (5–10 ml of 0.5% solution) has a moderate hypotensive effect - a sharp decrease in blood pressure can in this situation worsen the patient’s condition. The hypotensive effect of dibazole is due to a decrease in cardiac output and dilation of peripheral vessels due to its antispasmodic effect; after intravenous administration, it develops within 10–15 minutes and persists for 1–2 hours. Side effects: paradoxical short-term increase in blood pressure; sometimes – increased sweating, feeling hot, dizziness, headache, nausea, allergic reactions. Contraindications: severe heart failure, hypersensitivity to the drug.
Depending on the severity of the corresponding symptoms, additional administration of 10 ml of 2.4% theophylline
IV slowly (over 5 minutes), 10 mg
diazepam
IV;
IV infusion of mannitol
at a dose of 0.5–1.5 g/kg (up to 40 g), followed by IV administration of furosemide;
Dexamethasone
(4–8 mg IV) may be used
For GC with stroke
it is necessary to stabilize blood pressure at a level exceeding 5–10 mm Hg.
the patient's usual blood pressure level. To do this, use a slow (over 7–10 minutes or more) intravenous administration of magnesium sulfate
at a dose of 1000–2500 mg (as an exception, intramuscular administration of the drug in a warm form followed by warming the injection site is acceptable).
If there is a contraindication to the use of magnesium sulfate, nifedipine
at a dose of 5–20 mg p.i. (chew), and if it is impossible to use this route of administration (for example, in coma), dibazole IV (i.m.) at a dose of 30–40 mg.
In the case of GC with acute left ventricular failure
the use of narcotic analgesics is indicated (1 ml of 1% morphine solution intravenously in fractional streams), intravenous drip administration of nitrates (nitroglycerin or isosorbide dinitrate intravenous drip at a rate of 50–100 mcg/min, not more than 200 mcg/min).
The hypotensive effect develops within 2–5 minutes from the start of the infusion. Furosemide
is administered intravenously at a dose of 60–80 mg (up to 200 mg). The hypotensive effect develops 2–3 minutes after administration and is caused at the first stage by the vasodilating properties of the drug (dilates peripheral veins, reduces preload), and only then by the diuretic effect and decrease in blood volume. Diuretics do not replace the effect of other antihypertensive drugs (since in most cases a hypertensive crisis is caused by vasoconstriction with normal or even reduced blood volume), but complement and enhance their effect. It should be remembered that the use of nitrates and diuretics is not indicated when cerebral symptoms or eclampsia develop against the background of a crisis.
In case of GC with the development of a severe attack of angina or myocardial infarction
Intravenous administration of narcotic analgesics (morphine hydrochloride intravenously in a fractional stream) and nitrates (nitroglycerin or isosorbide dinitrate subcutaneously or intravenously in a drip) is also indicated.
If anginal status, tachycardia and rhythm disturbances develop against the background of a hypertensive crisis, and in the absence of signs of heart failure, intravenous administration of beta-blockers
(propranolol) is also advisable. A necessary condition is the ability to carefully monitor blood pressure, heart rate and ECG (due to the risk of developing bradycardia, atrioventricular block, etc.).
For GC with aortic dissection
in parallel with the relief of pain with morphine or morphine with droperidol, it is necessary to reduce myocardial contractility and quickly reduce blood pressure to the optimal level (100–120 mm Hg for systolic and no more than 80 mm Hg for diastolic).
The drugs of choice are propranolol
(1 mg every 3–5 minutes until the heart rate reaches 50–60 per minute, pulse pressure decreases to less than 60 mm Hg, or until a total dose of 0.15 mg/kg is reached, or until the appearance of side effects) and
sodium nitroprusside
, in its absence -
nitrates
(nitroglycerin, isosorbide dinitrate).
Sublingual administration of nifedipine (10–20 mg p.i., chewed) is acceptable. The administration of beta-blockers should precede the administration of any drugs that can cause tachycardia; if there are contraindications to the use of beta-blockers, use verapamil
at a dose of 5–10 mg intravenously (administered over 2–3 minutes); if necessary, it is possible to re-administer 5 mg of the drug after 5–10 minutes.
In case of GC with pronounced vegetative and psycho-emotional overtones (a variant of a panic attack), parenteral administration of drugs should be avoided; propranolol (20 mg) and diazepam (5–10 mg) should be used sublingually.
In case of GC as a result of discontinuation of clonidine, beta-blockers are contraindicated. Clonidine is used
p/ya at a dose of 0.075–0.15 mg, repeated every hour (until a clinical effect is obtained or until a total dose of 0.6 mg is achieved) or intravenously (less advisable intramuscularly) at a dose of 0.15 mg.
It should be noted that to date, parenteral administration of clonidine, magnesium sulfate, as well as dibazole and droperidol is most often used for the treatment of GC at the prehospital stage. At the same time, with a sudden increase in blood pressure, in most cases, sublingual use of drugs, in particular nifedipine, is necessary and sufficient. The use of clonidine is limited by the poor predictability of the effect (regardless of the dose of the drug, in addition to collapse, it is even possible to increase blood pressure due to the initial stimulation of peripheral beta-adrenergic receptors) and the high likelihood of side effects. Intramuscular administration of magnesium sulfate is painful and uncomfortable for the patient, and is also fraught with the development of complications, the most unpleasant of which is the formation of infiltrates in the buttocks. Dibazol does not have a pronounced hypotensive effect; its use is justified only if a cerebrovascular accident is suspected. Intravenous administration of propranolol requires a certain skill from the doctor due to the possibility of serious complications. The use of diazepam and droperidol is indicated only in cases of severe agitation of patients. It should be taken into account that sedatives and hypnotics can “lubricate” the neurological clinic, making it difficult to timely diagnose complications of GC, in particular, cerebrovascular accidents. The use of drugs that have an insufficient hypotensive effect (no-shpa, papaverine, etc.) for GC is certainly not justified.
Indications for hospitalization are formulated in national recommendations for the diagnosis and treatment of arterial hypertension (All-Russian Society of Cardiologists, Section of Arterial Hypertension, 2001). Emergency hospitalization
indicated in the following cases: HA that is not relieved at the prehospital stage; GC with severe manifestations of hypertensive encephalopathy; complications requiring intensive care and constant medical supervision (stroke, subarachnoid hemorrhage, acute visual impairment, pulmonary edema).
Use of magnesia for hypertension
Magnesia is considered a symptomatic drug, which does not mean that it should be used as a primary and permanent treatment for hypertension. The drug does not eliminate the cause of hypertension itself, but helps to cope with an exacerbation of the crisis in the shortest possible time and helps to improve the general condition of the patient. Therefore, it is impossible to treat hypertension with this measure alone.
In a critical situation, assistance is provided to the patient right on the spot in the form of an injection of a solution; in a hospital setting, droppers are used. It can be administered intramuscularly, but the injections are painful, and each of them increases the risk of complications.
What is the best way to use magnesium for pressure?
Currently, the most common method of introducing a substance into the body is injection into a vein: drip or drip. For these purposes, the release form in ampoules is used.
The choice of route of administration depends on the patient's condition and the criticality of the situation.
Oral administration of tablets does not affect blood pressure. To lower blood pressure, the drug is used only with a doctor's prescription. The course of treatment and dosage is determined by a specialist based on the general picture of the disease.
Intramuscularly
Currently, the method of intramuscular administration of the drug is considered outdated and is used very rarely. This situation is associated with the following problems:
- an injection is always associated with painful sensations;
- To obtain the result, it is necessary to introduce a sufficiently large amount of the drug, the amount of which can vary from 15 to 20 mm;
- Bruises or purulent inflammation often form at the puncture sites.
The drug is injected into the gluteal muscle area. A 25% solution is used for medicinal purposes 1 or 2 times a day, the injection volume is from 5 to 20 ml, the required amount is prescribed by the doctor. Because the procedure is painful, the solution is often used along with pain-relieving medications.
This option is chosen if the patient has problems with veins. After injection, the drug begins to act on average after 1 hour, the effect lasts 4 hours.
Intravenously
In emergency cases, magnesium in the form of a solution is administered intravenously with a quick and effective effect. The therapeutic effect is observed on average after 15 minutes. When the active substance is slowly introduced into the bloodstream, its level will gradually increase, which significantly reduces the risk of side effects.
The required dose is prescribed by the attending physician based on the general picture of the disease.
The dose of the solution may vary and is 15-20 ml. In hospitals, the drug is administered by drip; the rate of entry of the active substance into the body should not exceed 1 ml per minute. The drip is placed on average for 5-7 minutes.
Often, the jet injection method is practiced by emergency doctors in critical situations when there is a need to quickly reduce high blood pressure. At the same time, the speed of drug administration is controlled, focusing on the patient’s pulse. If the active substance enters your bloodstream quickly, you may feel hot, dizzy and nauseated. After administering the injection, the doctor observes for some time the process of normalization of the patient’s condition.
Orally
When administered orally, it is impossible to achieve a blood pressure lowering effect. Taking magnesium has a diuretic effect, acts as a laxative and helps calm cramps. This option is chosen when it is necessary to cleanse the intestines, remove toxins or eliminate pain in the abdominal area. The powder lasts for an average of 1.5 hours.
Intramuscular administration of magnesium to reduce blood pressure
To lower blood pressure, use 1 ampoule of a solution of 25% concentration in a volume of 10 ml. Since intramuscular injection is quite painful, magnesia is combined with Novocaine or Lidocaine. You can first inject an anesthetic drug, then inject magnesium, or mix both drugs in one syringe. For one ampoule of magnesia, take one ampoule of Novocain.
The procedure for administering magnesium to reduce blood pressure is carried out as follows:
- The patient is placed on his stomach or side.
- The needle is inserted into the upper part of the buttock, which is located away from the axis of the body. The skin area is first thoroughly treated with an alcohol solution.
- It is important to administer the drug slowly. The entire procedure cannot take less than 2 minutes.
- The needle should go deep into the soft tissue. It is inserted at a right angle.
When using magnesia in the form of injections, it must be remembered that there is an increased risk of the formation of infiltrates. For elderly patients, the drug should be used in a reduced dose, since their kidney function is reduced.
It should be understood that intramuscular administration of magnesium at high blood pressure has a very weak effect, especially when it comes to a hypertensive crisis. Sometimes intramuscular administration of magnesium is practiced in a hospital for persistent increases in blood pressure that are not controlled by other medications. The effect will be visible, but most often it is minor. Therefore, most modern doctors refuse to use this drug to lower blood pressure, especially when it comes to intramuscular injections. However, this drug is always present in the arsenal of the ambulance team.
Compatibility of magnesia with other drugs
Magnesia should not be consumed together with alcohol. The use of the drug with a number of drugs that contain calcium, barium, clindamycin phosphate, procaine and some other substances is unacceptable.
When magnesium reacts with the elements described above, a precipitate is formed.
Magnesia should be used with caution with hypnotics and psychotropic drugs, since their combined use leads to an increase in the effects of the latter. Concomitant use with narcotic drugs, barbiturates, and antihypertensive drugs can cause respiratory depression, so magnesia should not be used with such drugs.
Concomitant use with muscle relaxants or Nifedipine leads to increased neuromuscular blockade. In case of overdose, potassium salt should be administered intravenously, since this substance is an antidote and its use reduces the effect of magnesia.
When should magnesium not be used?
Like any other medicine, magnesia cannot always be used to lower blood pressure.
Contraindications to the use of the drug are:
- Atrioventricular block 1-3 degrees.
- The patient has hypersensitivity to magnesium.
- Kidney failure.
- Low blood pressure.
- Any body condition associated with a lack of calcium.
- Depression of respiratory function.
- Bradycardia.
- The period is two hours before the onset of labor.
- Any respiratory diseases.
- Exacerbations of diseases of the gastrointestinal tract.
Magnesia is prescribed with extreme caution to elderly people, pregnant and lactating women, and children. It should be borne in mind that in case of a hypertensive crisis, the drug is an auxiliary and not the main remedy used to relieve an attack.
