Magnesium sulfate - instructions for use, dose, side effects, contraindications

Pharmacodynamics:Ingestion has a laxative effect due to increased osmotic pressure in the lumen of the intestine and, as a consequence, fluid retention, which leads to an increase in the volume of intestinal contents and increased peristalsis. Has also a reflex choleretic effect (irritating the receptors of the mucous membrane of the duodenum). It is an antidote for poisoning with salts of heavy metals.
With parenteral administration has anticonvulsant, antiarrhythmic, hypotensive, spasmolytic action, in large doses - depresses the neuromuscular transmission, has a tocolytic effect, suppresses the respiratory center.
Mg2 + is a "physiological" blocker of slow calcium channels and is able to displace it from binding sites. Regulates metabolic processes, interneuronal transmission and muscular excitability, prevents Ca2 + from entering through the presynaptic membrane, reduces the amount of acetylcholine in the peripheral nervous system and CNS. Causes peripheral vasodilation, slows atrioventricular (AV) conduction and decreases heart rate. Relaxes smooth muscles, reduces blood pressure (mostly increased), increases diuresis.
Anticonvulsant action is associated with a decrease in the release of acetylcholine from neuromuscular synapses, suppression of neuromuscular transmission, a direct inhibitory effect on the central nervous system. The antiarrhythmic effect is due to a decrease in the excitability of cardiomyocytes, the restoration of ionic equilibrium, the stabilization of cell membranes, the violation of Na + current, the slow incoming current of Ca2 +, and the unidirectional current K +. The cardioprotective effect is provided by the expansion of the coronary arteries, the decrease in OPSS and platelet aggregation. Tocolytic action is associated with inhibition of the contractile ability of the myometrium (decrease in absorption,binding and distribution of Ca2 + in smooth muscle cells), increased blood flow in the uterus as a result of the expansion of its vessels (this action is not confirmed by data from randomized controlled clinical trials).

Pharmacokinetics:When taken orally, poorly absorbed (no more than 20%) in the jejunum and ileum, is reabsorbed from bile, pancreatic and intestinal juice. With the syndrome of malabsorption and the consumption of food rich in fats, the absorption of Mg2 + decreases. The onset of the effect is 0.5-3 hours, duration - 4-6 hours.
The therapeutic concentration in the plasma, sufficient to provide an anticonvulsant effect, is 2-3.5 mmol / l. Systemic effects develop almost instantly after IV and 1 hour after intravenous injection. The duration of action with / in the introduction - 30 minutes, with / m - 3-4 hours.
With any route of administration, it penetrates the GEB and the placental barrier, creating concentrations in the mother's milk that are 2 times higher than those in the plasma.
The connection with intracellular proteins and macroergic phosphates is 30%. TCmax - 4 h. Mg2 + is deposited in bones, skeletal muscles, kidneys, liver and myocardium; in small amounts - in the tissue fluid and red blood cells.
Excretion is carried out by the kidneys (the rate of renal excretion is proportional to the concentration in the plasma and the level of glomerular filtration) and with feces (with ingestion).

Indications:For oral administration: constipation, cholangitis, cholecystitis, dyskinesia of the gallbladder according to the hypotonic type (for carrying out tjubazhes), duodenal sounding (for obtaining a vesicle bile of bile), cleansing of the intestine before diagnostic manipulation. Poisoning with salts of heavy metals (mercury, arsenic, tetraethyl lead, barium).
For parenteral administration: arterial hypertension, hypertensive crisis (including with the phenomena of brain edema), eclampsia, encephalopathy, hypomagnesemia, incl. prevention (inadequate or unbalanced nutrition, intake of contraceptives, diuretics, muscle relaxants, chronic alcoholism), increased need for magnesium (pregnancy, growth period, recovery period, stress, excessive sweating), acute hypomagnesemia (signs of tetany, impaired myocardial function), threat of premature childbirth; ventricular arrhythmias associated with prolongation of the QT interval; ventricular tachycardia of the "pirouette" type; occurrence of arrhythmias against a low concentration of potassium and / or magnesium in blood plasma, epilepticsyndrome, urinary retention, poisoning with salts of heavy metals (mercury, arsenic, lead).

ICD-10

IV.E50-E64.E61.2 Magnesium deficiency

VI.G40-G47.G40 Epilepsy

IX.I10-I15.I10 Essential [primary] hypertension

IX.I10-I15.I15 Secondary Hypertension

IX.I30-I52.I47.2 Ventricular tachycardia

IX.I30-I52.I49 Other disorders of the heart rhythm

XI.K55-K63.K59.0 Constipation

XI.K80-K87.K81 Cholecystitis

XI.K80-K87.K82.8 Other specified diseases of the gallbladder

XI.K80-K87.K83.0 Cholangitis

XV.O10-O16.O15 Eclampsia

XV.O60-O75.O60 Premature birth

XVIII.R25-R29.R25.2 Cramp and spasm

XVIII.R30-R39.R33 Retention of urine

XIX.T51-T65.T56 Toxicity of metals

XIX.T51-T65.T65 Toxic effect of other and unspecified substances

XIX.T51-T65.T57 Toxic effect of other inorganic substances

XXI.Z40-Z54.Z51.4 Preparatory procedures for subsequent treatment, not elsewhere classified

Contraindications:Hypersensitivity, hypermagnia.
Additionally: for oral administration - appendicitis, rectal bleeding (including undiagnosed), intestinal obstruction, dehydration, acute inflammatory diseases of the digestive tract, pregnancy, breastfeeding; for parenteral administration - arterial hypotension, respiratory center depression, pronounced bradycardia, AV blockade, marked renal failure (creatinine clearance less than 20 ml / min), prenatal period (2 h before delivery).

Carefully:For interior purposes: heart block, myocardial damage, chronic renal failure.
For injection: myasthenia gravis, respiratory diseases, renal dysfunction, chronic renal failure, acute inflammatory diseases of the digestive tract, advanced age, pregnancy, lactation period, children's age.

Pregnancy and lactation:Action category for the fetus by FDA - D
Use with caution according to the prescription of the doctor and only in cases where the expected therapeutic effect exceeds the potential risk to the fetus.
When parenterally administered to pregnant women with preeclampsia and eclampsia, it easily penetrates the placental barrier and quickly reaches a fetal concentration plasma comparable to that in the mother's plasma. Side effects in the newborn are similar to those of the mother and include hypotension, inhibition, respiratory depression. Bone anomalies and congenital rickets in newborns are described, whose mothers were administered parenterally magnesium sulfate for a long time (4-13 weeks). Usually magnesium sulfate Do not apply in the prenatal period (2 hours before delivery), except when it is required to prevent convulsions in eclampsia.
It penetrates into breast milk, where concentration is twice as high as in the mother's blood. If it is necessary to use magnesium sulfate during lactation, breastfeeding should be discontinued.

Dosing and Administration:Individually, depending on the indications and the dosage form used. It is intended for oral, in / m and / in (slow) administration and injection through a duodenal probe.
Inside. As a laxative: adults - 20-30 g 1 time / day on an empty stomach, dissolved in 100 ml of warm water, children only as prescribed by the doctor at a rate of 1 g for 1 year of life.
As cholagogue for 15 ml of 20-25% solution 3 times / day, with duodenal probing 50 ml of 25% or 100 ml of 10% warm solution is injected through the probe.
When poisoning with salts of heavy metals, wash the stomach with 1% magnesium sulfate solution or give it inside (20-25 g in 200 ml of water to form insoluble barium sulfate).
The maximum dose for adults is up to 40 g / day.
Intramuscularly, intravenously: slowly 5-20 ml of 20-25% solution daily 1-2 times / day for 15-20 days.
Preeclampsia and eclampsia. The dose of saturation is 2-4 g after 5-20 minutes (infusion). The maintenance dose is 1-2 g / h.
Theta of the uterus. The dose of saturation is 4 g after 20 min (infusion). Maintenance dose: first 1-2 g / h, later 1 g / h (can be administered drip 24-72 h).
Hypomagnesemia. The newborn daily dose is 0.2-0.8 mg / kg IV slowly. Adults with severe form of the initial dose of 5 grams per liter of infusion solution iv in slowly.
Prevention of hypomagnesemia in patients receiving only parenteral nutrition. The daily dose is 1.5-4 g.
With hypertensive crises injected in / in 5,0-20 ml of 25% solution.
For arresting arrhythmias iv injection of 1-2 g for 5-10 minutes, possibly repeated administration.
When poisoning with mercury, arsenic, tetraethyl lead - in / in, 5-10 ml of 5-10% solution. For cramping seizures in children - in / m, 20-40 mg / kg (0.1-0.2 ml / kg of 20% solution).
The maximum daily intake of magnesium sulfate for adults is 40 g.

Side effects:When ingestion. Nausea, vomiting, diarrhea, exacerbation of inflammatory diseases of the digestive tract, electrolyte imbalance (fatigue, asthenia, confused consciousness, arrhythmia, convulsions), flatulence, abdominal pain of spastic nature, thirst, signs of hypermagnesia in the presence of kidney failure.
For parenteral administration. Early signs and symptoms of hypermagnesia - bradycardia, diplopia, sudden rush of blood to the skin of the face, headache, decreased blood pressure, nausea, shortness of breath, blurred speech, vomiting, weakness.
Signs of hypermagnia (in order of increasing serum Mg2 + concentrations): a decrease in deep tendon reflexes (2-3.5 mmol / l), prolongation of the PQ interval and expansion of the QRS complex on ECG (2.5-5 mmol / l), loss of deep tendon reflexes (4 -5 mmol / l), inhibition of the respiratory center (5-6.5 mmol / l), impaired conduction of the heart (7.5 mmol / l), cardiac arrest (12.5 mmol / l). In addition, hyperhidrosis, anxiety, deep sedation, polyuria, atony of the uterus.

Overdose:When ingestion. Symptoms: severe diarrhea. Treatment: symptomatic.
For parenteral administration. Symptoms: disappearance of the knee reflex (classic clinical sign of the onset of intoxication), nausea, vomiting, a sharp decrease in blood pressure, bradycardia, respiratory depression and central nervous system. Treatment: as an antidote, I / in (slowly) calcium preparations (calcium chloride or calcium gluconate 5-10 ml 10%), oxygen therapy, inhalation of carbogen, mechanical ventilation, peritoneal dialysis or hemodialysis, symptomatic agents (corrective functions of the central nervous system and cardiovascular system).

Interaction:Ingestion: reduces the effect of oral anticoagulants (incl.coumarin derivatives or derivatives of indanedione), cardiac glycosides, phenothiazines (especially chlorpromazine).
Reduces the absorption of ciprofloxacin, etidronic acid, antibiotics of the tetracycline group (forms unabsorbed complexes with oral tetracyclines), weakens the effects of streptomycin and tobramycin (laxative Mg2 + -containing drugs should be taken 1-2 hours after the application of the above drugs).
For parenteral administration: enhances the effect of other drugs, depressing the central nervous system.
Cardiac glycosides increase the risk of conduction disruption and AV blockade (especially with the simultaneous introduction of Ca2 + salts).
Muscle relaxants and nifedipine strengthen the neuromuscular blockade.
With the joint use of magnesium sulfate for parenteral administration with other vasodilators, the hypotensive effect may increase.
Barbiturates, narcotic analgesics, hypotensive drugs, when combined with magnesium sulfate, increase the likelihood of oppression of the respiratory center.
It interferes with the absorption of antibiotics of the tetracycline group, weakens the action of streptomycin and tobramycin.
Ca2 + salts reduce the action of magnesium sulfate.
With any route of administration is pharmaceutically incompatible with Ca2 + preparations, ethanol (in high concentrations), carbonates, bicarbonates and phosphates of alkali metals, arsenic acid, barium, strontium, clindamycin phosphate, hydrocortisone, sodium succinate, polymyxin In sulfate, procaine hydrochloride, salicylates and tartrates. At concentrations of Mg2 + above 10 mmol / ml in mixtures for complete parenteral nutrition, the separation of fat emulsions is possible.

Special instructions:Magnesium sulfate Inside should be taken occasionally, systematic use is not recommended. For oral administration, a solution for injection may be used as a laxative.
If necessary, simultaneous in / in the introduction of salts Mg2 + and Ca2 + they are injected into different veins. It is possible to use magnesium sulfate for relief of epileptic status (as part of complex therapy). Patients with severe renal dysfunction should not receive more than 20 g of magnesium sulfate within 48 hours, patients with oliguria or severe renal dysfunction should not be administered magnesium sulfate I / O too fast. It is recommended to monitor the concentration of Mg2 + in the serum (not higher than 0.8-1.2 mmol / l),diuresis (not less than 100 ml / 4 h), respiratory rate (not less than 16 / min), blood pressure, heart activity, tendon reflexes, kidney function. With parenteral use, special care should be taken not to create toxic concentrations. Elderly patients often require a dose reduction (due to weakened kidney function).
Due to magnesium sulfate in large doses depresses the neuromuscular transmission, during the period of treatment it is necessary to be cautious when driving vehicles and when practicing potentially dangerous activities that require an increased concentration of attention and speed of psychomotor reactions.

Instructions

Magnesium sulfate (Magnesii sulfas)