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

Pharmacodynamics:The drug has analgesic, antipyretic, anti-inflammatory effect, which is due to inhibition of cyclooxygenases 1 and 2, 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 systemic elimination in the intestinal wall and in the liver (deacetylated). Resorbed part is quickly hydrolyzed by special esterases, therefore the half-life period 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 required to reach the maximum concentration is 2 hours.

The serum level of salicylates is very variable. Salicylates easily penetrate into many tissues and body fluids, including spinal, 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 a non-ionized acid that penetrates well into the tissue, including the brain. Rapidly passes through the placenta, in small quantities is excreted in breast milk.

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 form (60%) and in the form of metabolites. Removal of unchanged salicylate depends on the pH of the urine (with alkalinization of urine ionization of salicylates increases, their reabsorption worsens and the excretion increases significantly). The rate of excretion depends on the dose: when taking small doses, the elimination half-life is 2-3 hours, with an increase in the dose it can increase to 15-30 hours.

Indications:

Symptomatic treatment of moderate or mild pain syndrome: headache (including abstinence syndrome), toothache, 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:

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

- 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 nasal polyposis and paranasal sinuses and intolerance to acetylsalicylic acid;

- Children under 6 years of age (for this dosage form).

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).

Dosing and Administration:

Take inside after eating with water, milk or alkaline mineral water.

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

Children aged 6 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), single dose is 0.25 g (1/2 tablet 0.5 g) per reception, the maximum daily dose - not more than 1.5 g per day.

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

Side effects:

From the central nervous system: dizziness, headache, visual impairment, reduced ear aches, tinnitus, aseptic meningitis.

From the gastrointestinal tract: nausea, decreased appetite, gastralgia, diarrhea, erosive-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 creatinine in the blood and hypercalcemia, papillary necrosis, acute renal failure, nephrotic syndrome, edema.

From the side of the liver: a violation of liver function, Reye syndrome (encephalopathy and acute fatty liver disease with rapid development of liver failure), increased activity of "liver" transaminases.

On the part of the hematopoiesis system: thrombocytopenia, anemia, leukopenia, hypocoagulation.

From the side of the cardiovascular system: increased symptoms of chronic heart failure.

Allergic reactions: skin rash, angioedema, bronchospasm.

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

Overdose:

Symptoms:

An overdose of light (a single dose of less than 150 mg / kg) and moderate (150-300 mg / kg) severity: nausea, vomiting, tinnitus, hearing loss, visual impairment, headache, dizziness, retardation, general malaise, fever . These symptoms occur when the dose is lowered or the drug is withdrawn.

Overdose of severe degree: hyperventilation of the lungs of the central genesis, respiratory alkalosis, metabolic acidosis, confused consciousness, drowsiness, collapse, convulsions, anuria, bleeding. Initially, central hyperventilation of the lungs leads to respiratory alkalosis - dyspnea, choking, cyanosis, cold sticky sweat; with increasing intoxication, paralysis of respiration and dissociation of oxidative phosphorylation, causing respiratory acidosis, increase.

In chronic overdose, the concentration determined in the plasma correlates poorly with the severity of intoxication. The greatest risk of development chronic intoxication is noted in the elderly with the intake for several days more than 100 mg / kg / day. In children and elderly patients, the initial signs of salicylism are not always noticeable, so it is advisable to periodically determine the salicylate content in the blood: a concentration above 70 mg% indicates moderate or severe poisoning; above 100 mg% - about extremely severe, prognostically unfavorable. With 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. The increase in reserve alkalinity increases the excretion of acetylsalicylic acid due to alkalinization of urine. The alkalinization of urine is indicated at a salicylate concentration above 40 mg% and is provided by intravenous infusion of sodium bicarbonate (88 mEq / in 1 L of 5% dextrose solution, at a rate of 10-15 ml / h / kg), alkaline diuresis until a pH of urine between 7.5- 8 (forced alkaline diuresis is considered to be 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); the restoration of the volume of circulating blood and the induction of diuresis are achieved by the introduction of sodium bicarbonate in the same doses and dilutions, which are 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 for alkalinization of urine (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 lower in the presence of indications (refractory acidosis, progressive deterioration, severe central nervous system damage, pulmonary edema and kidney failure). With pulmonary edema - artificial ventilation light mixture, enriched in oxygen.

Interaction:

Interactions that are contraindicated:

Methotrexate at a dose of more than 15 mg per week: the hematologic toxicity of methotrexate is increased, because non-steroidal anti-inflammatory drugs generally reduce the renal clearance of methotrexate, and salicylates, in particular, displace it from the connection with plasma proteins.

Combinations of drugs that are used with caution:

Methotrexate in a dose of less than 15 mg / week: the hematologic toxicity of methotrexate is increased, because non-steroidal anti-inflammatory drugs generally reduce the renal clearance of methotrexate, and salicylates in particular displace it from the bond with plasma proteins.

Anticoagulants (heparin): increased risk of bleeding due to suppression of platelet function,damage to the mucous membrane of the stomach and duodenum and displacement of oral anticoagulants from their association with proteins

Other non-steroidal anti-inflammatory drugs with high-dose salicylates (≥3 g / day): increased risk of ulcers of the gastrointestinal mucosa and bleeding due to synergistic effect.

Urikozuric drugs (benzbromarone, probenecid): the uricosuric effect is reduced due to competitive tubular elimination of uric acid.

Digoxin: the concentration of digoxin in the plasma is increased, due to a decrease in renal excretion.

Hypoglycemic drugs (insulin, sulfonylureas): hypoglycemic effect is increased due to the fact that acetylsalicylic acid in high dose has hypoglycemic properties and displaces sulfonylurea from the connection with plasma proteins.

Thrombolytics and antiplatelet agents (ticlopidine): increases the risk of bleeding.

Diuretics in combination with acetylsalicylic acid at a dose of 3 g / day or more: glomerular filtration decreases, due to a decrease in the synthesis of prostaglandins in the kidneys.

Systemic glucocorticosteroids, with the exception of hydrocortisone, as glucocorticosteroids reduce the elimination of salicylates, the concentration of salicylates in the blood decreases during their use, and after the elimination there is a risk of overdose of salicylates.

Angiotensin converting enzyme inhibitors: acetylsalicylic acid at a dose of 3 g / day or more causes a decrease in glomerular filtration, due to inhibition of the synthesis of prostaglandins. Further, a decrease in the hypotensive effect of angiotensin converting enzyme inhibitors is observed.

Valproic acid: increases the toxicity of valproic acid due to its displacement from the bond with proteins.

Alcohol: when combined with acetylsalicylic acid, the damaging effect on the mucous membrane of the gastrointestinal tract increases and the time of bleeding lengthens.

Strengthens the effects of narcotic analgesics, thrombolytic agents and inhibitors of platelet aggregation, sulfonamides (including co-trimoxazole).

Increases the concentration of barbiturates, lithium salts in plasma.

Antatsida 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:

Children can prescribe drugs containing acetylsalicylic acid in cases that exclude acute respiratory infections caused by viral infections, since in the case of a viral infection, the risk of developing Reye syndrome increases. Symptoms of Reye's syndrome are: prolonged vomiting, acute encephalopathy, enlargement of the 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, and allergic reactions to other drugs (eg, itching, hives, other skin reactions).

The ability of acetylsalicylic acid to inhibit platelet aggregation can lead to increased bleeding during and after surgery (including minor surgical interventions, such as tooth extraction). The risk of bleeding increases with the use of acetylsalicylic acid in a high dose.

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 excretion.

Form release / dosage:

Tablets of 500 mg.

Packaging:

For 10 tablets in a contour non-cellular package made of paper with a polymer or polyethylene coating.

For 10 tablets in a contour mesh package made of polyvinyl chloride film EP-73 and aluminum foil printed lacquered.

Contour-free cell or cell packs, together with an equal number of instructions for use, are placed in a group package.

Storage conditions:

In a dry place.

Keep out of the reach of children.

Shelf life:

4 years.

Do not use after the time specified on the package.

Terms of leave from pharmacies:Without recipe

Registration number:P N001715 / 01-2003

Date of registration:25.11.2008 / 18.05.2012

Expiration Date:Unlimited

The owner of the registration certificate:DALHIMFARM, OJSC DALHIMFARM, OJSC Russia

Manufacturer: & nbsp

DALHIMFARM, OJSC Russia

Information update date: & nbsp02.10.2017

Illustrated instructions

Instructions

Acetylsalicylic acid (Acetylsalicylic acid)