Aspirin tablets 500mg, No. 20

• Symptomatic treatment of moderate or mild pain syndrome: headache (including with withdrawal symptoms), toothache, back and muscle pain, joint pain, pain during menstruation.

• Increased body temperature with 'colds' and other infectious and inflammatory diseases (in adults and children over 15 years old).

Take orally after meals with water, milk or alkaline mineral water.

Adults and children over 15 years of age: a single dose is 0.25-0.5 g, the maximum single dose for adults is 1.0 g (2 tablets 0.5 g each), the maximum daily dose is 3.0 g (6 tablets 0, 5 d), a single dose, if necessary, can be taken 3-4 times a day with an interval of at least 4 hours.

Children over the age of 6, with the exception of acute respiratory diseases caused by viral infections, due to the risk of developing Reye's syndrome (encephalopathy and acute fatty degeneration of the liver with acute development of liver failure), a single dose is 0.25 g (1/2 tablet 0.5 g) per reception, the maximum daily dose is not more than 1.5 g per day.

The duration of treatment (without consulting a doctor) should not exceed 5 days when prescribed as an anesthetic and more than 3 days as an antipyretic agent.

Composition for one tablet:

Active substance: Acetylsalicylic acid - 500 mg.

Excipients: Potato starch - 81.78 mg; Talc - 12 mg; Citric acid - 0.22 mg; Calcium stearate - 6 mg

• Erosive and ulcerative lesions of the gastrointestinal tract (in the acute phase);

• gastrointestinal bleeding;

• hemorrhagic diathesis;

• hypersensitivity to acetylsalicylic acid, other salicylates or any excipients of the drug; - bronchial asthma induced by the intake of salicylates and non-steroidal anti-inflammatory drugs;

• combined use with methotrexate at a dose of 15 mg per week or more;

• I and III trimesters of pregnancy and the period of breastfeeding;

• complete or incomplete combination of bronchial asthma, recurrent polyposis of the nose and paranasal sinuses and acetylsalicylic acid intolerance;

• children under 6 years of age (for this dosage form).

• The drug is not prescribed for children under 15 years of age with acute respiratory diseases caused by viral infections, due to the risk of developing Reye's syndrome (encephalopathy and acute fatty liver disease with acute development of liver failure).

  Carefully:

• With concomitant therapy with anticoagulants, gout, gastric ulcer and / or duodenal ulcer (in history), including chronic or recurrent peptic ulcer disease, or episodes of gastrointestinal bleeding; with renal and / or hepatic failure, deficiency of glucose-6-phosphate dehydrogenase; hyperuricemia, bronchial asthma, chronic obstructive pulmonary disease, hay fever, nasal polyposis, drug allergy, simultaneous administration of methotrexate at a dose of less than 15 mg / week, pregnancy (II trimester).

Pharmacodynamics

The drug has an analgesic, antipyretic, anti-inflammatory effect, which is due to the inhibition of cyclooxygenases 1 and 2 involved in the synthesis of prostaglandins. Acetylsalicylic acid inhibits platelet aggregation by blocking the synthesis of thromboxane A2.

Pharmokinetics

When taken orally, absorption is complete. During absorption, it undergoes systemic elimination in the intestinal wall and in the liver (deacetylated). The resorbed part is rapidly hydrolyzed by special esterases, therefore the half-life is no more than 15-20 minutes. It circulates in the body (75-90% due to albumin) and is distributed in tissues in the form of the anion of salicylic acid. The time required to reach maximum concentration is 2 hours. Serum salicylate levels are highly variable. Salicylates easily penetrate into many tissues and body fluids, including cerebrospinal, peritoneal and synovial fluids. Penetration into the joint cavity is accelerated in the presence of hyperemia and edema and slows down in the proliferative phase of inflammation. In small amounts, salicylates are found in the brain tissue, traces - in bile, sweat, feces.When acidosis occurs, most of the salicylic acid is converted to non-ionized acid, which penetrates well into tissues, including the brain. It quickly passes through the placenta, in small quantities it is excreted in breast milk. It is metabolized mainly in the liver with the formation of 4 metabolites found in many tissues and urine. It is excreted mainly by active secretion in the tubules of the kidneys. unchanged (60%) and in the form of metabolites. The excretion of unchanged salicylate depends on the pH of the urine (with alkalinization of the urine, the ionization of salicylates increases, their reabsorption worsens and the excretion significantly increases). The rate of elimination depends on the dose: when taking small doses, the half-life is 2-3 hours, with an increase in the dose it can increase to 15-30 hours.

Overdose

Symptoms:

Overdose of mild (single dose less than 150 mg / kg) and moderate (150-300 mg / kg) severity: nausea, vomiting, tinnitus, hearing loss, visual impairment, headache, dizziness, lethargy, general malaise, fever ... These symptoms disappear when the dose is reduced or the drug is discontinued. Severe overdose: pulmonary hyperventilation of central origin, respiratory alkalosis, metabolic acidosis, confusion, drowsiness, collapse, convulsions, anuria, bleeding. Initially, central hyperventilation of the lungs leads to respiratory alkalosis - shortness of breath, suffocation, cyanosis, cold clammy sweat; with increased intoxication, respiratory paralysis and uncoupling of oxidative phosphorylation increase, causing respiratory acidosis. In case of chronic overdose, concentration,determined in plasma correlates poorly with the severity of intoxication. The greatest risk of developing chronic intoxication is observed in the elderly when taken for several days more than 100 mg / kg / day. In children and elderly patients, the initial signs of salicylism are not always noticeable, therefore, it is advisable to periodically determine the content of salicylates in the blood: a concentration above 70 mg% indicates moderate or severe poisoning; above 100 mg% - about extremely severe, prognostically unfavorable. In case of moderate and severe poisoning, hospitalization is necessary.therefore, it is advisable to periodically determine the content of salicylates in the blood: a concentration above 70 mg% indicates moderate or severe poisoning; above 100 mg% - about extremely severe, prognostically unfavorable. In case of moderate and severe poisoning, hospitalization is necessary.therefore, it is advisable to periodically determine the content of salicylates in the blood: a concentration above 70 mg% indicates moderate or severe poisoning; above 100 mg% - about extremely severe, prognostically unfavorable. In case of moderate and severe poisoning, hospitalization is necessary.

Treatment:

provocation of vomiting, the appointment of activated carbon and laxatives, constant monitoring of the acid-base state and electrolyte balance; depending on the state of metabolism - the introduction of sodium bicarbonate, sodium citrate solution or sodium lactate. An increase in reserve alkalinity enhances the excretion of acetylsalicylic acid due to alkalization of urine. Alkalization of urine is indicated at salicylate concentrations above 40 mg% and is provided by intravenous infusion of sodium bicarbonate (88 mEq in 1 liter of 5% dextrose solution, at a rate of 10-15 ml / h / kg), alkaline diuresis until a urine pH of between 7.5- 8 (forced alkaline diuresis is considered achieved if the concentration of salicylate in the blood plasma is more than 500 mg / l (3.6 mmol / l) in adults or 300 mg / l (2.2 mmol / l) in children);restoration of the circulating blood volume and induction of diuresis are achieved by the introduction of sodium bicarbonate in the same doses and dilution, which is repeated 2-3 times. Caution should be exercised in elderly patients in whom intensive fluid infusion can lead to pulmonary edema. It is not recommended to use acetazolamide to alkalize urine (it can cause acidosis and enhance the toxic effect of salicylates). Hemodialysis is indicated at a salicylate concentration of more than 100-300 mg%, in patients with chronic poisoning - 40 mg% and below if indicated (refractory acidosis, progressive deterioration, severe damage to the central nervous system, pulmonary edema and renal failure). With pulmonary edema - artificial ventilation of the lungs with a mixture enriched with oxygen.

Side effects

From the side of the central nervous system: dizziness, headache, visual impairment, hearing loss, tinnitus, aseptic meningitis. From the gastrointestinal tract: nausea, loss of appetite, gastralgia, diarrhea, erosive and ulcerative lesions of the gastrointestinal tract, bleeding from the gastrointestinal tract. From the side of the kidneys: impaired renal function; interstitial nephritis, prerenal azotemia with increased blood creatinine and hypercalcemia, papillary necrosis, acute renal failure, nephrotic syndrome, edema. From the liver: abnormal liver function, Reye's syndrome (encephalopathy and acute fatty degeneration of the liver with the rapid development of liver failure), increased activity of 'hepatic' transaminases. From the hematopoietic system: thrombocytopenia, anemia, leukopenia,hypocoagulation. On the part of the cardiovascular system: increased symptoms of chronic heart failure. Allergic reactions: skin rash, angioedema, bronchospasm. If such symptoms appear, it is recommended to stop taking the drug and immediately consult your doctor.

Special conditions

Children can be prescribed drugs containing acetylsalicylic acid in cases that exclude acute respiratory diseases caused by viral infections, since in the case of a viral infection, the risk of Reye's syndrome increases. Symptoms of Reye's syndrome are: prolonged vomiting, acute encephalopathy, enlarged liver. Acetylsalicylic acid can provoke the development of bronchospasm and cause an attack of bronchial asthma or other allergic reactions. Risk factors are the patient's history of bronchial asthma, hay fever, nasal polyposis, chronic respiratory diseases, as well as allergic reactions to other drugs (for example, itching, urticaria, other skin reactions).The ability of acetylsalicylic acid to inhibit platelet aggregation can lead to increased bleeding during and after surgery (including minor surgery such as tooth extraction). The risk of bleeding increases with high-dose acetylsalicylic acid. In low doses, acetylsalicylic acid reduces the excretion of uric acid, which can lead to the development of gout in patients with an initially low level of its excretion.