ASA Drug Information [ Shoppers Drug Mart ]

Table of content

ASA category:

• Human
• Analgetics Acetaminophen Salicylates Codeine
• Salicylates

Active ingredients:

• Aspirin

ASA companies and manufacturers:

• Shoppers Drug Mart

General Information

ASA forms, composition and dosages:

• Tablet, Enteric Coated; Oral; Aspirin 325 mg
• Tablet, Enteric Coated; Oral; Aspirin 650 mg
• Tablet; Oral; Aspirin 325 mg

Indications, usages and classification codes:

• B01AC06 - Acetylsalicylic Acid
• N02BA01 - Acetylsalicylic Acid

There is an additional general information about this medication active ingredient aspirin (acetylsalicylic acid):

Pharmacological action

NSAIDs. It has anti-inflammatory, analgesic and antipyretic effect, and inhibits platelet aggregation. The mechanism of action is associated with inhibition of COX activity - the main enzyme metabolism of arachidonic acid which is a precursor of prostaglandins which play a major role in the pathogenesis of inflammation, pain and fever. Reduction of prostaglandins (mainly E1) in the thermoregulation center leads to a decrease in body temperature due to expansion of blood vessels of the skin and increase perspiration. Analgesic effect is due to both central and peripheral effects. Reduces aggregation, platelet adhesion and thrombus formation through suppression of synthesis of thromboxane A2 in platelets.
Reduces mortality and risk of myocardial infarction in unstable stenocardia. It is effective in primary prevention of cardio-vascular system and secondary prevention of myocardial infarction. At a daily dose of 6 g or more inhibits the synthesis of prothrombin in the liver and increases the prothrombin time. Increases fibrinolytic activity of plasma and reduces the concentration of vitamin K-dependent coagulation factors (II, VII, IX, X). Increases the rate of hemorrhagic complications in carrying out surgical procedures, increases the risk of bleeding during therapy with anticoagulants. It stimulates the excretion of uric acid (violating its reabsorption in the renal tubules) but in high doses. The blockade of COX-1 in the mucosa of the stomach leads to inhibition of gastroprotective prostaglandins, which may lead to ulceration of the mucous membrane and subsequent bleeding.

Pharmacokinetics

When administered orally is rapidly absorbed mainly from the proximal small intestine and to a lesser extent from the stomach. The presence of food in the stomach significantly affects the absorption of acetylsalicylic acid.
Metabolised in the liver by hydrolysis with the formation of salicylic acid with subsequent conjugation with glycine or two drugs. The concentration of salicylates in blood plasma is variable.
About 80% of salicylic acid binds to plasma proteins. Salicylates easily penetrate into many tissues and body fluids, including the cerebrospinal, peritoneal and synovial fluid. In small quantities salicylates are found in brain tissue, traces - in bile, sweat and feces. Quickly penetrates the placental barrier in small amounts excreted in breast milk.
For newborns salicylates may displace bilirubin from its association with albumin and promote bilirubin encephalopathy.
Penetration into the joint cavity is accelerated in the presence of hyperemia and edema, and slows down in the proliferative phase of inflammation.
If you have acidosis most of salicylate becomes unionized acid, good penetration into the tissue, including in the brain.
Withdraws mainly by active secretion in the tubules of the kidneys in unchanged form (60%) and in the form of metabolites. The withdraw of unchanged salicylate is dependent on the pH of urine (for alkalinization of urine increases ionized salicylates, worsening their reabsorption and increases excretion). T1/2 of acetylsalicylic acid is approximately 15 minutes. T1/2 of salicylate at a reception in low doses is 2-3 h, with an increase in dose may increase to 15-30 hours. Newborns' elimination of salicylate is much slower than in adults.

Why is ASA by Shoppers Drug Mart prescribed?

Rheumatism, rheumatoid arthritis, infectious-allergic myocarditis, fever during infectious and inflammatory diseases, pain syndrome, weak and medium intensity of various origins (including neuralgia, myalgia, headache); based prevention of thrombosis and embolism, primary and secondary prevention of myocardial infarction, prevention of violations of cerebral circulation by ischemic type.
In the clinical immunology and allergy: a gradually increasing doses for a prolonged "aspirin" desensitization and the formation of stable tolerance to NSAIDs in patients with "aspirin asthma" and "aspirin triad."

Dosage and administration

Individual. For oral administration dosing regimen depends on indication for use. Usual adult dose when used as antipyretic and analgesic is 500-1000 mg / day (up to 3 g) were divided into 3 admission.
In myocardial infarction, as well as for secondary prevention in patients after myocardial infarction - 40-325 mg 1 time a day (usually 160 mg). As an inhibitor of platelet aggregation - a dose of 300-325 mg / day, for a long time. At the dynamic circulatory disorders in men, cerebral thromboembolism, including to prevent a recurrence - 325 mg / day with gradual increase to a maximum of 1 g / day. For prevention of thrombosis or occlusion of the aortic shunt - by 325 mg every 7 h after intranasal gastric tube set, and then - through the mouth to 325 mg 3 times a day (usually in combination with dipyridamole, which abolished after 1 week, continuing the long-term treatment with acetylsalicylic acid).

ASA by Shoppers Drug Mart side effects

Digestive system: nausea, vomiting, anorexia, epigastric pain, diarrhea; rarely - occurrence of erosive and ulcerative lesions, bleeding from the gastrointestinal tract, abnormal liver function.
Central nervous system: long-term use may be dizziness, headache, reversible visual disturbances, tinnitus, aseptic meningitis.
Hemopoietic system: rarely - thrombocytopenia, anemia.
Blood coagulation system: rarely - haemorrhagic syndrome, prolongation of bleeding time.
Urinary system: rarely - renal dysfunction, with prolonged use - acute kidney failure, nephrotic syndrome.
Allergic reactions: rarely - skin rash, Quincke's edema, bronchospasm, "aspirin triad" (a combination of bronchial asthma, recurrent nasal polyposis, and paranasal sinuses and intolerance of acetylsalicylic acid and medicines pirazolonic series).
Other: in some cases - Reye syndrome, long-term use - increased symptoms of chronic heart failure.

Contraindications

Exacerbation phase of erosive-ulcerative lesions in the gastrointestinal tract, gastro-intestinal bleeding, "aspirin triad", a history of indications urticaria, rhinitis, caused by taking aspirin and other NSAIDs, hemophilia, hemorrhagic diathesis, gipoprotrombinemii, dissecting aneurysm of the aorta, portal hypertension, deficiency of vitamin K, liver and / or renal failure, deficiency of glucose-6-phosphate dehydrogenase, Reye syndrome, children's age (under 15 years - the risk of developing Reye syndrome in children with hyperthermia on a background of viral diseases), I and III trimester of pregnancy, lactation, hypersensitivity to aspirin and other salicylates.

Using during pregnancy and breastfeeding

aspirin (acetylsalicylic acid) is contraindicated in I and III trimester of pregnancy. In pregnancy trimester II can a one-off reception on the strict condition.
This medication has a teratogenic effect: when used in the I trimester leads to top palatoschisis, in the III trimester - cause inhibition of labor (inhibition of prostaglandin synthesis), premature closure of the ductus arteriosus in the fetus, pulmonary vascular hyperplasia and hypertension in the pulmonary circulation.
aspirin (acetylsalicylic acid) is excreted in breast milk, which increases the risk of bleeding in a child due to dysfunction of platelets, and therefore should not be applied acetylsalicylic acid in the mother during lactation.

Special instructions

With caution used in patients with liver diseases and kidney, bronchial asthma, erosive and ulcerative lesions, and bleeding from the digestive tract in history, with increased bleeding or while holding anticoagulant therapy, decompensated congestive heart failure.
Acetylsalicylic acid even in small doses reduces the excretion of uric acid from the organism that can cause an acute attack of gout in predisposed patients. When conducting long-term therapy and / or use of aspirin in high doses required medical supervision and regular monitoring of hemoglobin levels.
The use of acetylsalicylic acid as anti-inflammatory drugs in a daily dose of 5-8 g is limited due to the high probability of adverse effects from the gastrointestinal tract.
Before surgery to reduce bleeding during surgery and postoperative period should stop taking salicylates for 5-7 days.
During prolonged therapy is necessary to conduct a general analysis of blood and study of occult blood.
The use of acetylsalicylic acid is contraindicated in pediatrics, as in the case of viral infection in children under the influence of acetylsalicylic acid increases the risk of developing Reye syndrome. Symptoms of Reye syndrome are prolonged vomiting, acute encephalopathy, liver enlargement.
Duration of treatment (without consulting a doctor) should not exceed 7 days when administered as analgesic and more than 3 days as an antipyretic.
During treatment the patient should abstain from alcohol.

Precautionary measures

Undesirable combined use with other NSAIDs and glucocorticoids. For 5-7 days before surgery should stop taking (to reduce bleeding during surgery and postoperative period).
The probability of NSAID-gastropathy decreases in the appointment after a meal, use of tablets with buffer additives or coated with a special enteric-soluble shell. The risk of hemorrhagic complications is minimal when used in doses less than 100 mg / day.
Note that in predisposed patients acetylsalicylic acid (even in small doses) reduces the excretion of uric acid from the body and can cause the development of acute attack of gout.
During prolonged therapy should regularly carry out the analysis of blood and to investigate faeces for occult blood. In connection with the observed cases hepatogenic encephalopathy is not recommended for relief of fever syndrome in children.

ASA by Shoppers Drug Mart drug interactions

With simultaneous use of antacids containing magnesium and / or aluminum hydroxide, slow down and reduce the absorption of acetylsalicylic acid.
With simultaneous use of calcium channel blockers, means limiting intake of calcium or increasing the excretion of calcium from the body, increases the risk of bleeding.
With simultaneous use with acetylsalicylic acid enhances the action of heparin and indirect anticoagulants, hypoglycemic funds derived sulfonylureas, insulin, methotrexate, phenytoin, valproic acid.
With simultaneous use of SCS increases the risk of ulcerogenic effect and occurrence of gastrointestinal bleeding.
With simultaneous use of decreasing the effectiveness of diuretics (spironolactone, furosemide).
With simultaneous use of other NSAIDs increases the risk of side effects. Acetylsalicylic acid may reduce plasma concentrations indomethacin, piroxicam.
With simultaneous use of gold drugs acetylsalicylic acid can induce liver damage.
With simultaneous use decreases effectiveness of uricosuric medications (including probenecid, sulfinpirazon, benzbromarone).
With simultaneous use of acetylsalicylic acid and alendronate sodium may develop severe esophagitis.
With simultaneous use of griseofulvin may be in breach Absorption of acetylsalicylic acid.
There is one case of spontaneous hemorrhage in the iris while taking Ginkgo Biloba extract on the background of prolonged use of aspirin in a dose of 325 mg / day. It is believed that this may be due to additive inhibitory effect on platelet aggregation.
With simultaneous use of dipyridamole may increase C_max of salicylate in plasma and AUC.
When applied simultaneously with acetylsalicylic acid increased concentration of digoxin, barbiturates and lithium salts in the blood plasma.
With simultaneous use of salicylates in high doses with carbonic anhydrase inhibitors can intoxication salicylates.
Acetylsalicylic acid in doses of less than 300 mg have little effect on the effectiveness of captopril and enalapril. When aspirin (acetylsalicylic acid) is admistered in high doses may decrease the effectiveness of captopril and enalapril.
With simultaneous application of caffeine increases the rate of absorption, plasma concentrations and bioavailability of acetylsalicylic acid.
With simultaneous use of metoprolol may increase C_max of salicylate in blood plasma.
In the application of pentazocine on the background of long-term use of aspirin in high doses there is a risk of severe adverse reactions in the kidneys.
With simultaneous application phenylbutazone reduces uricosuria caused by acetylsalicylic acid.
With simultaneous application of ethanol may exacerbate the effects of acetylsalicylic acid on the gastrointestinal tract.

ASA by Shoppers Drug Mart in case of emergency / overdose

May occur after receiving a single large dose or prolonged use. If a single dose of less than 150 mg / kg, acute poisoning feel light, 150-300 mg / kg - moderate, when using higher doses - heavy.
Symptoms: salicylism syndrome (nausea, vomiting, tinnitus, blurred vision, dizziness, severe headache, malaise, fever - a poor prognostic sign in adults). More severe poisoning - stupor, convulsions and coma, noncardiogenic pulmonary edema, abrupt dehydration, violations ABE (initially - respiratory alkalosis, then - metabolic acidosis), renal failure and shock.
In chronic overdose concentration determined in plasma are poorly correlated with the severity of intoxication. The greatest risk of chronic intoxication is found among elderly people at reception for a few days more than 100 mg / kg / day. In children and elderly patients the initial signs of salicylism are not always visible, and therefore desirable to periodically determine the concentration of salicylates in the blood. Level above 70 mg% indicates moderate or severe poisoning; above 100 mg% - on extremely heavy, a poor prognosis. If poisoning moderate require hospitalization for at least 24 hours.
Treatment: the provocation of vomiting, the appointment of activated charcoal and laxatives, monitoring ABE and electrolyte balance, depending on the state of metabolism - the introduction of sodium bicarbonate, solution of sodium citrate or sodium lactate. Raising reserve alkalinity increases the excretion of acetylsalicylic acid by alkalinization of urine. Alkalinization of urine is shown at the level of salicylates above 40 mg%, is provided in / by infusion of sodium bicarbonate - 88 mEq in 1 liter of 5% glucose solution, the rate of 10-15 ml / kg / h. Restoring BCC and induction of diuresis (achieved by introducing a bicarbonate in the same dose and dilution, repeat 2-3 times); should be aware that intense infusion fluid elderly patients may lead to pulmonary edema. Not recommended the use of acetazolamide for alkalinization of urine (may cause acidemia and enhance the toxic effect of salicylates). Hemodialysis is shown at the level of salicylates over 100-130 mg%, and in patients with chronic poisoning - 40 mg% or lower in the presence of witnesses (refractory acidosis, progressive deterioration, severe damage of the CNS, pulmonary edema and renal failure). When pulmonary edema - a mixture of artificial ventilation, oxygen enriched, in the mode of positive end-expiratory pressure, to treat cerebral edema apply hyperventilation and osmotic diuresis.

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