Acetylsalicylic acid - instructions for use, dose, side effects, contraindications

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

Pharmacokinetics:

At intake the absorption is complete. During absorption, it undergoes presystemic elimination in the intestinal wall and in the liver (deacetylated).The absorbed part is quickly hydrolyzed by nonspecific cholinesterases of plasma and albumin esterase, therefore the elimination half-life is no more than 15-20 minutes.

In the body it circulates (75-90% in association with albumin) and is distributed in tissues as an anion of salicylic acid.

The time to reach the maximum concentration is 2 hours. The serum concentration of salicylates is very variable. Salicylates easily penetrate into many tissues and body fluids, including. in spinal, peritoneal and synovial fluid. 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 nervous tissue, traces in bile, sweat, feces. When acidosis occurs, most of the salicylic acid is converted to a non-ionized acid that penetrates well into the tissue, including. in the brain. Rapidly passes through the placenta, in small quantities is excreted in breast milk. Metabolized mainly in the liver. Metabolites of acetylsalicylic and salicylic acids are glycine conjugate of salicylic acid, gentisic acid and its glycine conjugate.It is excreted mainly by active secretion in the renal tubules in the form of salicylic acid (60%) and in the form of metabolites. Excretion salicylic acid depends on the pH of the urine (urine alkalinization increases the ionization of salicylates, their reabsorption deteriorates and the excretion increases significantly). The rate of excretion depends on the dose: when taking small doses, the period P2-3 hours with increasing dose may increase to 15-30 hours

Indications:

Treatment of moderate or mild pain syndrome: headache (including with abstinence syndrome), toothache, sore throat, back and muscle pain, joint pain, menstruation pain.

Elevated body temperature with "colds" and other infectious and inflammatory diseases (in adults and children over 15 years old).

Contraindications:

- Pincreased sensitivity to acetylsalicylic acid and other NSAIDs or other components of the drug;

- erosive-ulcerative lesions of the gastrointestinal tract (GIT) (in the phase of exacerbation);

- gastrointestinal bleeding;

- hemorrhagic diathesis;

- combined use of methotrexate in a dose of 15 mg per week or more;

- complete or incomplete combination of bronchial, asthma, recurrent nasal polyposis and paranasal sinuses and intolerance to acetylsalicylic acid;

- The bronchial asthma, induced by the intake of salicylates and other NSAIDs;

- pregnancy (I and III trimester), the period of breastfeeding;

- Children's age (up to 15 years - when used as an antipyretic agent). The drug is not prescribed for children under 15 with acute respiratory infections caused by viral infections, because of 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, peptic ulcer and / or duodenal ulcer (in the anamnesis), including chronic or recurrent peptic ulcer disease, or episodes of gastrointestinal bleeding; with renal and / or hepatic insufficiency, deficiency of glucose-6-phosphate dehydrogenase; hyperuricemia, bronchial asthma, chronic obstructive pulmonary disease, hay fever, nasal polyposis, drug allergy, concomitant use of methotrexate in a dose of less than 15 mg / week, pregnancy (II trimester).

Pregnancy and lactation:

In pregnancy, the use of the drug is contraindicated.

If you need to use the drug during lactation, breastfeeding should be discontinued.

Dosing and Administration:

Inside, adults and children over 12 years of age: a single dose of 250-500 mg, the maximum single dose of 1.0 g (2 tablets of 500 mg), a maximum daily dose of 3.0 g (6 tablets of 500 mg), a single dose of You can take 3-4 times a day with an interval of at least 4 hours.

Children (as an anesthetic) aged 6 to 12 years, with the exception of acute respiratory infections caused by viral infections, because of the risk of developing Reye's syndrome (encephalopathy and acute fatty liver disease with acute development of liver failure), a single dose of 250 mg at the reception, take up to 3 times a day.

Mode of application: the drug should be taken after meals, washed down with water, milk or alkaline mineral water.

Frequency and time of admission: a single dose, if necessary, can be taken 3-4 times a day with an interval of at least 4 hours. Regular adherence to the regimen allows you to avoid a sharp increase in temperature and reduce the intensity of the pain syndrome.

The duration of treatment (without consulting a doctor) should not exceed 7 days when prescribed as an anesthetic and more than 3 days - as an antipyretic.

Side effects:

From the gastrointestinal tract: loss of appetite, abdominal pain, heartburn, nausea, vomiting, obvious (vomiting with blood, tarry stools) or hidden signs of gastrointestinal bleeding that can lead to iron deficiency anemia, erosive-ulcerative lesions (including perforations) of the gastrointestinal hemorrhage, intestinal tract, single cases - violations of the liver (increase hepatic transaminases), diarrhea.

From the central nervous system: dizziness, tinnitus (usually a sign of an overdose); with prolonged use - headache, visual impairment, decreased acuity of hearing, aseptic meningitis.

From the cardiovascular system: with prolonged use - increased symptoms of chronic heart failure.

On the part of the hematopoiesis system: increased risk of bleeding, which is a consequence of the effect of acetylsalicylic acid on platelet aggregation, thrombocytopenia, anemia, and leukopenia.

From the excretory system: impaired renal function; with prolonged use - interstitial nephritis, prerenal azotemia with increased creatinine in the blood and hypercalcemia, papillary necrosis, acute renal failure, nephrotic syndrome, edema.

Allergic reactions: skin rash, anaphylactic reactions, bronchospasm, angioedema.

Reye's syndrome (encephalopathy and acute fatty liver dystrophy with rapid development of liver failure).

When such symptoms appear, it is recommended to stop taking the drug and immediately consult a doctor.

Overdose:

Symptoms

Overdose of moderate severity: nausea, vomiting, tinnitus, hearing impairment, headache, dizziness and confusion. These symptoms occur when the dose is lowered or the drug is withdrawn.

Severe overdose: fever, hyperventilation, ketoacidosis, respiratory alkalosis, metabolic acidosis, coma, cardiogenic shock, respiratory failure, severe hypoglycemia.

With chronic overdose the concentration determined in plasma does not correlate well with the severity of intoxication.The greatest risk of developing chronic intoxication is observed in the elderly with more than 100 mg / kg / day for several days. In children and elderly patients, the initial signs of salicylism are not always noticeable, so it is advisable to periodically determine the concentration of salicylates in the blood: a concentration above 70 mg% indicates moderate or severe poisoning; above 100 mg% - about extremely severe, predictive unfavorable. When poisoning the moderate and severe degree of severity, hospitalization is necessary.

Treatment: hospitalization, gastric lavage, reception of activated charcoal, monitoring of acid-base balance, alkalinization of urine in order to obtain a urine pH between 7.5-8 (forced alkaline diuresis is 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), hemodialysis, fluid loss compensation, symptomatic therapy. Caution should be exercised in elderly patients in whom intensive fluid infusion can lead to pulmonary edema. It is not recommended to use acetazolamide for alkalinization of urine (can cause acidosis and enhance the toxic effect of salicylates).Hemodialysis is indicated with a salicylate concentration of more than 100-130 mg%, in patients with chronic poisoning - 40 mg% and lower in the presence of indications (refractory acidosis, progressive deterioration, severe central nervous system damage, pulmonary edema and kidney failure).

When swelling of the lungs - artificial ventilation of the lungs with a mixture enriched with oxygen.

Interaction:

Joint application:

- with methotrexate at a dose of 15 mg per week or more is a contraindication: the hemolytic cytotoxicity of methotrexate is increased (decreased renal clearance of methotrexate and methotrexate is replaced by salicylates in association with blood plasma proteins);

- with anticoagulants, for example, heparin: increased risk of bleeding due to a violation of platelet function, damage to the mucous membrane of the gastrointestinal tract, the displacement of anticoagulants (indirect) from the connection with plasma proteins;

- with other non-steroidal anti-inflammatory drugs: as a result of synergistic interaction, the risk of ulcers and bleeding from the stomach and duodenum increases;

- with uricosuric medicines, for example, benzbromarone: reduces the uricosuric effect;

- with digoxin: the concentration of digoxin is increased due to decreased renal excretion;

- with hypoglycemic drugs: hypoglycemic effect of hypoglycemic drugs increases due to hypoglycemic effect of acetylsalicylic acid;

- with preparations of the thrombolytics group: the fibrinolytic effect of the latter increases and the risk of bleeding increases;

- with glucocorticosteroids, excluding hydrocortisone, used as substitution therapy for Addison's disease: when glucocorticosteroids are used, the concentration of salicylates in the blood decreases due to an increase in the excretion of the latter;

- with inhibitors of the angiotensin-converting enzyme: glomerular filtration is reduced by inhibiting the synthesis of prostaglandins and, as a consequence, the antihypertensive effect is reduced;

- with valproic acid: the toxicity of valproic acid increases;

- with glucocorticosteroids, ethanol (alcoholic beverages) and ethanol-containing medicines: the risk of damage to the mucous membrane increasesthe envelope of the gastrointestinal tract, the risk of developing gastrointestinal bleeding increases;

- intensifies the effects of narcotic analgesics, indirect anticoagulants and antiaggregants, sulfonamides (including co-trimoxazole - strengthens them activity and toxicity), triiodothyronine (increases activity and increases the risk of side effects of the latter);

- reduces the effect of antihypertensive drugs, diuretics (spironolactone, furosemide);

- increases the concentration of barbiturates, lithium salts in plasma;

- antacids containing magnesium and / or aluminum slow down and worsen the absorption of acetylsalicylic acid;

- Myelotoxic drugs increase the manifestation of hematotoxicity of the drug.

Special instructions:

Acetylsalicylic acid can cause bronchospasm, an attack of bronchial asthma or other hypersensitivity reactions. Risk factors are the presence of bronchial asthma, polyps of the nose, fever, chronic bronchopulmonary diseases, cases of allergy in the anamnesis (allergic rhinitis, rashes on the skin). Acetylsalicylic acid can increase the tendency to bleeding, which is due to its inhibitory effect on platelet aggregation. This should be considered when surgical interventions are required, including such minor interventions as tooth extraction. Before surgery, to reduce bleeding during surgery and in the postoperative period, you should cancel taking the drug for 5-7 days and inform the doctor.

Children should not be prescribed drugs containing acetylsalicylic acid, because in the case of a viral infection, the risk of developing Reye syndrome increases. Symptoms of Reye's syndrome include prolonged vomiting, acute encephalopathy, and enlargement of the liver.

Acetylsalicylic acid reduces the excretion of uric acid from the body, which can cause an acute attack of gout in predisposed patients.

Acetylsalicylic acid has a teratogenic effect; when applied in the first trimester leads to the development of cleavage of the upper palate; in the III trimester causes inhibition of labor (inhibition of prostaglandin synthesis), premature closure of the arterial duct in the fetus, hyperplasia of pulmonary vessels and hypertension in the small circulation.Isolated with breast milk, which increases the risk of bleeding in the child due to impaired platelet function.

During treatment should refrain from taking ethanol.

Effect on the ability to drive transp. cf. and fur:

There is no evidence of the effect of taking the drug on driving a vehicle and other mechanisms that may affect the ability to drive vehicles,

Form release / dosage:

Tablets 500 mg.

Packaging:

10 tablets per contoured, cell-free or cell packaging: One or two contour packs, together with the instructions for use, are placed in a pack of cardboard boxes. Contour non-cellular packages, together with an equal number of instructions for use, are placed in a group package.

Storage conditions:

Store in a dry, protected from light place, at a temperature of no higher than 25 ° C. Keep out of the reach of children.

Shelf life:

4 years.

Do not use the drug after the expiration date.

Terms of leave from pharmacies:Without recipe

Registration number:P N003627 / 01

Date of registration:24.06.2009 / 23.08.2010

Expiration Date:Unlimited

The owner of the registration certificate:MOSCOW PHARMACEUTICAL FACTORY, CJSC MOSCOW PHARMACEUTICAL FACTORY, CJSC Russia

Manufacturer: & nbsp

MOSCOW PHARMACEUTICAL FACTORY, CJSC Russia

Information update date: & nbsp02.10.2017

Illustrated instructions

Instructions

Acetylsalicylic acid (Acetylsalicylic acid)