Pharmacodynamics: The drug is a derivative of pyrazolone. The mechanism of action is associated with non-selective blocking of cyclooxygenase and a decrease in the formation of prostaglandins from arachidonic acid. It interferes with pain extra- and intra-receptive impulses along the Gaulle and Burdach beams, increases the threshold of excitability of the thalamic centers of pain sensitivity, and increases heat transfer. A distinctive feature is the slight severity of the anti-inflammatory effect, which leads to a weak effect on the water-salt metabolism (delay of Na + and water) and the gastrointestinal mucosa. It has an analgesic, antipyretic and some antispasmodic (in relation to the smooth muscles of the urinary and biliary tract) effect.
Pharmacokinetics: With intramuscular (i/m) administration, it is rapidly absorbed and enters the liver, where it undergoes hydrolysis with the formation of an active metabolite, unchanged metamizole sodium is found in the blood in small quantities only after intravenous (i/v) administration. In blood, it reversibly binds to plasma proteins 50-60%. The main part of the drug is excreted in the urine in the form of metabolites. Metabolites also pass into breast milk. With repeated administration of the drug, its pharmacokinetics does not change.
Indications for use: Feverish syndrome in acute infectious, purulent and urological diseases (prostatitis), insect bites (mosquitoes, bees, gadfly, etc.), post-transfusion complications. Pain syndrome (mild to moderate severity): incl. neuralgia, sciatica, myalgia, arthralgia, biliary-hepatic colic, intestinal colic, renal colic, injuries, burns, decompression sickness, herpes zoster, orchitis, radiculitis, rheumatism, myositis, postoperative pain, headache, toothache, menstrual pain, algodismenorea, chorea, with pulmonary infarction, myocardial infarction, stratified aortic aneurysm, major vessel thrombosis, inflammatory processes (pleurisy, pneumonia, lumbago, myocarditis), decompression illness, tumors, pancreatitis, peritonitis, perforum tion esophagus, pneumothorax, priapism, etc.
Dosage and administration: I / m or I /v in (especially with severe pain).
Adults – 250-500 mg 3 times a day. The maximum single dose is 1 g, the daily dose is 2 g. Children are prescribed at a rate of 5-10 mg / kg 2-3 times a day. For children up to a year, the drug is administered only intramuscularly.
The injectable solution for injection should have a body temperature. Doses of more than 1 g should be administered i/v.
Conditions for antishock therapy are necessary. The most common cause of a sharp decrease in blood pressure is an injection rate that is too high, and therefore iv can be administered slowly (at a speed of not more than 1 ml / min), while the patient is lying down, under the control of blood pressure, heart rate and number breaths.
Side effects: From the urinary system: impaired renal function, oliguria, anuria, proteinuria, interstitial nephritis, urine staining in red.
Allergic reactions: urticaria (including on the conjunctiva and mucous membranes of the nasopharynx), Quincke’s edema, in rare cases – malignant exudative erythema (Stevens-Johnson syndrome), toxic epidermal necrolysis (Lyell syndrome), bronchospastic syndrome, anaphylactic shock.
From the hemopoietic organs: agranulocytosis, leukopenia, thrombocytopenia.
Other: lowering blood pressure.
Local reactions: with i / m administration, infiltrates at the injection site are possible.
Contraindications: Hypersensitivity, suppression of blood formation (agranulocytosis, cytostatic or infectious neutropenia), liver and / or renal failure, hereditary hemolytic anemia associated with deficiency of glucose-6-phosphate dehydrogenase, “aspirin” asthma, anemia, leukopenia, pregnancy and especially in the first three last 6 weeks), lactation, children up to 3 months, peptic ulcer of the stomach and duodenum in the acute stage.
With caution: the period of the newborn (up to 3 months), kidney disease (pyelonephritis, glomerulonephritis – including a history), prolonged abuse of ethanol. Patients with systolic blood pressure below 100 mm Hg or with instability of blood circulation (for example, against the background of myocardial infarction, multiple trauma, beginning shock).
Drug interactions: Due to the high likelihood of pharmaceutical incompatibility, it cannot be mixed with other drugs in the same syringe. Enhances the effect of ethanol; simultaneous use with chlorpromazine or other phenothiazine derivatives can lead to the development of severe hyperthermia (fever). X-ray contrast agents, colloidal blood substitutes, and penicillin should not be used during treatment with metamizole. With the simultaneous administration of cyclosporine, the concentration of the latter in the blood decreases. Metamizole, displacing oral hypoglycemic drugs, indirect anticoagulants, glucocorticosteroids and indomethacin from a protein bond, increases their activity. Phenylbutazone, barbiturates, and other hepatoinductors with simultaneous administration reduce the effectiveness of metamizole. Simultaneous administration with other non-narcotic analgesics, tricyclic antidepressants, hormonal contraceptives and allopurinol can lead to increased toxicity. Sedatives and anxiolytic drugs (tranquilizers) enhance the analgesic effect of metamizole. Tiamazole and cytostatics increase the risk of developing leukopenia. The effect is enhanced by codeine, H2-histamine blockers and propranolol (slows down inactivation).
Special instructions: With caution and under the supervision of a physician, the drug should be used in patients with impaired liver and / or kidney function, with a tendency to hypotension, bronchospasm, with increased sensitivity to non-narcotic analgesics or non-steroidal anti-inflammatory drugs. During the treatment with the drug, you can not use alcohol. Particular care is required when introducing 2 ml of the solution or more (risk of a sharp decrease in blood pressure). When using large doses of the drug or with its prolonged use, it is necessary to control the blood picture and the state of the liver. For children and adolescents under 18 years of age, the drug should be used only as directed by a doctor. Metamizole metabolites can stain urine red.
Influence on the ability to drive a car and other mechanisms.
It is not recommended to drive vehicles and engage in other potentially hazardous activities that require quick physical and mental reactions.
The drug should be stored out of the reach of children and not used after the expiration date.
Overdose: Symptoms: nausea, vomiting, gastralgia, oliguria, hypothermia, decreased blood pressure, tachycardia, shortness of breath, tinnitus, drowsiness, delirium, impaired consciousness, acute agranulocytosis, hemorrhagic syndrome, acute renal and / or liver failure, convulsions, respiratory muscles paralysis.
Treatment: induction of vomiting, through tube gastric lavage, saline laxatives, activated charcoal; conducting forced diuresis, hemodialysis, with the development of convulsive syndrome – i /v introduction of diazepam and rapidly acting barbiturates.
Release form: 2 ml in ampoules of neutral or colorless glass. On 10 ampoules in a blister strip packaging from a film of polyvinyl chloride. The blister strip packaging is placed in a cardboard pencil case, instructions for use are placed in each pencil case.
Storage conditions: Store in a dry, dark place at a temperature not exceeding 25°C.
Shelf life: 3 years.
Pharmacy sales terms: On prescription.