Aspirin
Aspirin Medication Information:
Aspirin medication comes in several different strengths; click on the strength you need to view prices from pharmacies competing to earn your business.
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Aspirin 100 mg
NO Rx
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Aspirin 325 mg
NO Rx
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Aspirin With Stomach guard 325 mg
NO Rx
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Pharmacology
ASA interferes with the production of prostaglandins in various organs and tissues through acetylation of the enzyme cyclo-oxygenase. Prostaglandins are themselves powerful irritants and produce headaches and pain on injection in man. Prostaglandins also appear to sensitize pain receptors to other noxious substances such as histamine and bradykinin. By preventing the synthesis and release of prostaglandins in inflammation, ASA may avert the sensitization of pain receptors.
The antipyretic activity of ASA is due to its ability to interfere with the production of prostaglandin E1 in the brain. Prostaglandin E1 is one of the most powerful pyretic agents known.
The inhibition of platelet aggregation by ASA is due to its ability to interfere with the production of thromboxane A2 within the platelet. Thromboxane A2 is largely responsible for the aggregating properties of platelets.
When ASA is taken orally, it is rapidly absorbed from the stomach and proximal small intestine. The gastric mucosa is permeable to the nonionized form of ASA, which passes through the stomach wall by a passive diffusion process.
Optimum absorption of salicylate in the human stomach occurs in the pH range of 2.15 to 4.10. Absorption in the small intestine occurs at a significantly faster rate than in the stomach. After an oral dose of 650 mg ASPIRIN, the plasma acetylsalicylate concentration in man usually reaches a level between 0.6 and 1.0 mg% in 20 minutes after ingestion and drops to 0.2 mg% within an hour. Within the same period of time, half or more of the ingested dose is hydrolyzed to salicylic acid by esterases in the gastrointestinal mucosa and the liver, the total plasma salicylate concentration reaching a peak between 1 or 2 hours after ingestion, averaging between 3 and 7 mg%. Many factors influence the speed of absorption of ASA in a particular individual at a given time; tablet disintegration, solubility, particle size, gastric emptying time, psychological state, physical condition, nature and quantity of gastric contents, etc., all affect absorption.
Distribution of salicylate throughout most body fluids and tissues proceeds at a rapid rate after absorption. Aside from the plasma itself, fluids which have been found to contain substantial amounts of salicylate after oral ingestion include spinal, peritoneal and synovial fluids, saliva and milk. Tissues containing high concentrations of the drug are the kidney, liver, heart and lungs. Concentrations in the brain are usually low, and are minimal in feces, bile and sweat.
The drug readily crosses the placental barrier. At clinical concentrations, from 50% to 90% of the salicylate is bound to plasma proteins especially albumin, while ASA itself is bound to only a very limited extent. However, ASA has the capacity of acetylating various proteins, hormones, DNA, platelets and hemoglobin, which at least partly explains its wide-ranging pharmacological actions.
The liver appears to be the principal site for salicylate metabolism, although other tissues may also be involved. The three chief metabolic products of salicylic acid are salicyluric acid, the ether or phenolic glucuronide and the ester or acyl glucuronide. A small fraction is also converted to gentisic acid and other hydroxybenzoic acids. The half-life of ASA in the circulation is from 13 to 19 minutes so that the blood level drops quickly after absorption is complete. However, the half-life of the salicylate ranges between 3.5 and 4.5 hours, which means that 50% of the ingested dose leaves the circulation within that time.
Excretion of salicylates occurs principally via the kidney, through a combination of glomerular filtration and tubular excretion, in the form of free salicylic acid, salicyluric acid, as well as phenolic and acyl glucuronides. Salicylate can be detected in the urine shortly after its ingestion but the full dose requires up to 48 hours for complete elimination. The rate of excretion of free salicylate is extremely variable, reported recovery rates in human urine ranging from 10% to 85%, depending largely on urinary pH. In general, it can be stated that acid urine facilitates reabsorption of salicylate by renal tubules, while alkaline urine promotes excretion of the drug.
Indications
The relief of pain, fever and inflammation of a variety of conditions such as influenza, common cold, low back and neck pain, dysmenorrhea, headache, toothache, sprains and strains, myositis, neuralgia, synovitis, arthritis, bursitis, burns, injuries, following surgical and dental procedures.
ASPIRIN Extra Strength is also indicated for relief of migraines including pain and the associated symptoms of photophobia (sensitivity to light) and phonophobia (sensitivity to sound), and improves overall quality of life.
ASPIRIN 325 mg or ASPIRIN 81 mg is indicated for the following uses, based on its platelet aggregation inhibitory properties:
For reducing the risk of vascular mortality in patients with a suspected acute myocardial infarction.
For reducing the risk of a first non-fatal myocardial infarction in individuals deemed to be at sufficient risk of such an event by their physician. There is no evidence for a reduction in the risk of a first fatal myocardial infarction.
ASPIRIN does not reduce the risk of either cardiovascular mortality of first strokes, fatal or non-fatal.
The decrease in the risk of first non-fatal myocardial infarction must be assessed against a much smaller but not insignificant increase in risk of haemorrhagic stroke as well as gastrointestinal bleeding.
For reducing the risk of morbidity and death in patients with unstable angina and in those with previous myocardial infarction.
For reducing the risk of transient ischemic attacks (TIA) and for secondary prevention of atherothrombotic cerebral infarction.
Prophylaxis of venous thromboembolism after total hip replacement. (ASPIRIN 325 mg only).
Reduction of the adhesive properties of the platelets in patients following carotid endarterectomy to prevent recurrence of TIA and in hemodialysis patients with a silicone rubber arteriovenous cannula. (ASPIRIN 325 mg only).
Precautions
See Warnings.
Supplied
ASPIRIN Children's Size
Each peach-colored tablet, with a pleasant orange taste, with the Bayer Cross on one side and ASPIRIN in a semicircle along the circumference of the other, contains: ASA 80 mg USP. Nonmedicinal ingredients: cornstarch, dextrose, FD&C Yellow #6, orange juice flavor and sodium cyclamate. Bottles of 24 and 90.
ASPIRIN with Stomach Guard Extra Strength 500 mg Caplets
Each white, film-coated caplet, with BAYER PLUS over 500 on one side in blue ink, contains: ASA 500 mg, calcium carbonate 246.2 mg, magnesium carbonate 52.3 mg and magnesium oxide 96.9 mg. Nonmedicinal ingredients: carnauba wax, cornstarch, croscarmellose sodium, FD&C Blue #2, hydrogenated vegetable oil, hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, polysorbate 80, polyvinylpyrrolidone, propylene glycol, silicon dioxide, sodium lauryl sulfate, talc, titanium dioxide and triacetin. Packages of 60.
ASPIRIN Tablets, 325 mg
Each white tablet, with the Bayer Cross on both sides, contains: ASA 325 mg. Nonmedicinal ingredients: cornstarch, hypromellose, powdered cellulose and triacetin. Blister packages of 8 and bottles of 24, 50, 100 and 200.
ASPIRIN Caplets, 325 mg
Each white, capsule-shaped tablet (caplet), with BAYER on one side and a score on the other, contains: ASA 325 mg. Nonmedicinal ingredients: cornstarch, hypromellose, powdered cellulose and triacetin. Packages of 50 and 100.
ASPIRIN Extra Strength Tablets, 500 mg
Each white tablet, with the Bayer Cross in red ink on one side, contains: ASA 500 mg. Nonmedicinal ingredients: carnauba wax, cornstarch, D&C Red #7, FD&C Blue #2, FD&C Red #40, hypromellose, powdered cellulose, propylene glycol, shellac, titanium dioxide and triacetin. Packages of 50 and 100.
ASPIRIN 81 mg Quick Chews
Each peach-coloured tablet, with the Bayer Cross on one side, contains: ASA 81 mg. Nonmedicinal ingredients: corn starch, dextrose, FD&C Yellow # 6, orange flavour and sodium cyclamate. Bottles of 30 and 100.
ASPIRIN Arthritis Pain Relief Caplets, 325 mg
Each pale yellow, enteric coated caplet, with BAYER 325 in brown ink on one side, contains: ASA 325 mg. Nonmedicinal ingredients: black and brown iron oxides, carnauba wax, cornstarch, D&C Yellow #10, FD&C Yellow #6, hypromellose, methacrylic acid copolymer, polysorbate 80, powdered cellulose, sodium lauryl sulfate, talc, titanium dioxide, triacetin and triethyl citrate. Bottles of 50, 100 and 200.
ASPIRIN Express Pack
Each pouch contains: ASA 500 mg. Nonmedicinal ingredients: ascorbic acid, aspartame, citric acid (anhydrous), cola flavour, mannitol, orange flavour, sodium dihydrogen citrate and sodium hydrogen carbonate. Packages of 10 and 32 single dose pouches.
ASPIRIN with Stomach Guard 325 mg Tablets
Each round, white, film-coated tablet, with BAYER PLUS in blue ink on one side, contains: ASA 325 mg, calcium carbonate 160 mg, magnesium carbonate 34 mg and magnesium oxide 63 mg. Nonmedicinal ingredients: carnauba wax, cornstarch, croscarmellose sodium, FD&C Blue #2, hydrogenated vegetable oil, hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, polysorbate 80, polyvinylpyrrolidone, propylene glycol, silicon dioxide, sodium lauryl sulfate, talc, titanium dioxide and triacetin. Packages of 36.
ASPIRIN 81 mg
Each pale blue, enteric coated tablet, with 81 in dark blue ink on one side, contains: ASA 81 mg. Nonmedicinal ingredients: carnauba wax, cornstarch, croscarmellose sodium, FD&C Blue #1, FD&C Blue #2, hypromellose, lactose monohydrate, methacrylic acid copolymer, microcrystalline cellulose, polysorbate 80, powdered cellulose, propylene glycol, shellac, sodium lauryl sulfate, starch, titanium dioxide and triacetin. Bottles of 30, 120 and 180.
ASPIRIN Arthritis Pain Relief Extra Strength Caplets, 500 mg
Each pale yellow, enteric coated caplet, with BAYER 500 in brown ink on one side, contains: ASA 500 mg. Nonmedicinal ingredients: black and brown iron oxides, carnauba wax, cornstarch, D&C Yellow #10, FD&C Yellow #6, hypromellose, methacrylic acid copolymer, polysorbate 80, powdered cellulose, sodium lauryl sulfate, talc, titanium dioxide, triacetin and triethyl citrate. Bottles of 100.
Contraindications
Patients who are hypersensitive to this drug or to any ingredient in the formulation or component of the container (see Supplied); patients with a history of asthma induced by the administration of salicylates or substances with a similar action, notably nonsteroidal anti-inflammatory drugs; combination with methotrexate at doses of 15 mg/week or more; last trimester of pregnancy; hemorrhagic diathesis; active peptic ulcer.
Warnings
ASPIRIN and other NSAIDs
The use of other nonsteroidal anti‑inflammatory drugs with salicylates at high doses (equal to/more than 3 g/day) may increase the risk of ulcers and gastrointestinal bleeding due to a synergistic effect.
Drug Interactions
ASPIRIN should be used with caution with other products that have anticoagulation or antiplatelet effects, as these effects may be potentiated. Drugs that bind to protein binding sites should also be used cautiously since ASPIRIN may displace drugs from their protein binding site.
Valproic Acid
Salicylates may alter valproic acid (VPA) metabolism and may displace VPA from protein binding sites, possibly intensifying the effects of VPA. Caution is recommended when VPA is administered concomitantly with salicylates.
Lactation
ASPIRIN and its metabolites pass into breast milk in small quantities. Since no adverse effects on the infant have been observed after occasional use, interruption of breast-feeding is usually unnecessary. However, on regular use or on intake of high doses, breast feeding should be discontinued early.
A possible association between Reye's syndrome and the use of salicylates has been suggested but not established. Reye's syndrome has also occurred in many patients not exposed to salicylates.
ASPIRIN should not be used in children and teenagers for viral infections with or without fever without consulting a physician.
In certain viral illnesses, especially influenza A, influenza B and varicella, there is a risk of Reye’s syndrome, a very rare but possibly life-threatening illness requiring immediate medical action. The risk may be increased when ASPIRIN is given concomitantly; however, no causal relationship has been proven. Should persistent vomiting occur with such diseases; this may be a sign of Reye’s syndrome.
At low doses, ASPIRIN reduces excretion of uric acid. This can trigger gout in patients who already tend to have low uric acid excretion.
Salicylates can produce changes in thyroid function tests.
Isolated cases of liver function disturbances (transaminases increase) have been described.
Angiotensin Converting Enzyme (ACE) Inhibitors
The hyponatremic and hypotensive effects of ACE inhibitors may be diminished by the concomitant administration of ASPIRIN due to its indirect effect on the renin-angiotensin conversion pathway. The potential interaction may be related to the dose of ASPIRIN (3 g/day or more).
Ibuprofen
Ibuprofen may interfere with the cardioprotective effects and platelet aggregation inhibitory properties of ASPIRIN. Patients should talk to their doctor if they are on an ASPIRIN regimen and take ibuprofen for pain. Studies have shown that single doses and multiple doses of ibuprofen may interfere with the anti-platelet effects of low dose ASPIRIN.
Glucocorticoids (systemic), except hydrocortisone used as replacement therapy in Addison’s disease
Decreased blood salicylate levels during corticosteroid treatment and risk of salicylate overdose after this treatment is stopped via increased elimination of salicylates by corticosteroids.
Pregnancy
Use of salicylates in the first 3 months of pregnancy has been associated in several epidemiological studies with an elevated risk of malformations (cleft palate, heart malformations). After normal therapeutic doses this risk seems to be low: a prospective study with exposure of about 32 000 mother-child pairs has not yielded any association with the risk of malformations.
Salicylates should be taken during pregnancy only after strict risk-benefit evaluation.
In the last 3 months of pregnancy administration of salicylates in high doses (>300 mg/day) can lead to prolongation of the gestation period, premature closure of the arterial duct and inhibition of uterine contractions. An increased hemorrhagic tendency has been observed in both mother and child.
Administration of ASPIRIN in high doses (>300 mg/day) shortly before birth can lead to intracranial hemorrhages, particularly in premature babies.
Anticoagulants, e.g. warfarin, heparin
Caution is necessary when salicylates and anticoagulants are prescribed concurrently, as salicylates can depress the concentration of prothrombin in the plasma.
Oral hypoglycemics, e.g. insulin, sulfonylureas
Large doses of salicylates have a hypoglycemic action and may enhance the effect of oral hypoglycemic agents. Diabetics receiving concurrent salicylate and hypoglycemic therapy should be monitored closely: reduction of the sulfonylurea hypoglycemic drug dosage may be necessary.
Diuretics
Sodium excretion produced by spironolactone may be decreased by salicylate administration.
Uricosuric Agents
Salicylates in large doses are uricosuric agents; smaller amounts may depress uric acid clearance and thus decrease the uricosuric effects of other drugs.
Methotrexate, used at 15 mg/week or less
Salicylates may retard the elimination of methotrexate by decreasing renal clearance of methotrexate, displacing methotrexate from protein binding sites, and thereby increasing its hematological toxicity.
Digoxin
Plasma concentrations of digoxin are increased due to a decrease in renal excretion.
Adverse Effects
Miscellaneous
mental confusion, drowsiness, sweating, thirst.
Gastrointestinal
(the frequency and severity of these adverse effects are dose-related): nausea, vomiting, diarrhea, gastrointestinal bleeding and/or ulceration, dyspepsia, heartburn, hematemesis, melena.
Hematologic
leukopenia, thrombocytopenia, purpura, anemia.
Ear
tinnitus, vertigo, hearing loss.
Dermatologic and Hypersensitivity
urticaria, angioedema, pruritus, skin eruptions, asthma, anaphylaxis, Quincke edema.
Overdose
Severe Overdose
All of the symptoms from moderate overdose plus hypotension, hallucinations, stupor, hypoglycemia, convulsions, cerebral edema, oliguria, renal failure, cardiovascular failure, coma, hemorrhage, metabolic acidosis, respiratory alkalosis and/or failure.
Mild Overdose or Early Poisoning
Burning in the mouth, lethargy, nausea, vomiting, tinnitus, sweating, thirst, tachycardia or dizziness.
Symptoms
Moderate Overdose
All of the symptoms from mild overdose plus tachypnea, hyperpyrexia, sweating, dehydration, loss of coordination, restlessness, mental confusion.
Treatment
Emergency Management: Immediate transfer to hospital and maintain cardiovascular and respiratory support. Gastric lavage, administration of activated charcoal. Check of acid-base balance and correct if necessary. Alkaline diuresis so as to obtain urine pH between 7.5 and 8 should be considered when plasma salicylate concentration is greater than 500 mg/L (3.6 mmol/L) in adults or 300 mg/L (2.2 mmol/L) in children. Hemodialysis should be considered in severe poisoning 800 mg/L (5.8 mmol/L) in adults and 700 mg/L (5.0 mmol/L) in children, as renal elimination of salicylates may be slow due to the presence of acidic urine and renal failure. Hemodialysis should also be considered if the patient is experiencing severe systemic metabolic acidosis (arterial pH <7.2), acute renal failure, pulmonary edema or CNS symptoms such as: drowsiness, agitation, coma or convulsions. Fluid losses should be replaced with hypotonic solution (e.g. half saline) and supplemented with glucose 50 to 100 g/L. Symptomatic treatment. Fatal Dose: varies from 10 to 30 g of ASA. However, (in one case) 130 g of ASA was ingested without fatal outcome.
Dosage
Analgesic and Antipyretic: Adults: 1 to 2 tablets (325 to 650 mg) orally every 4 hours. Children under 12: 10 to 15 mg/kg every 6 hours, not to exceed total daily dose of 2.4 g.
Migraine Pain and Associated Symptoms: Adults: 1000 mg (2×500 mg tablets) at onset of pain or symptoms. Children: Clinical studies to support migraine relief in children have not been conducted with acetylsalicylic acid.
Anti-inflammatory: Adults: 3 tablets (975 mg) 4 to 6 times a day, up to 30 tablets daily, may be required for optimal anti-inflammatory effect. A blood level between 15 and 30 mg/100 mL is in the desirable therapeutic range.
Children: 60 to 125 mg/kg daily in 4 to 6 divided doses.
Platelet Aggregation Inhibitor: Suspected Acute Myocardial Infarction: An initial dose of at least 160-162.5 mg chewed or crushed to ensure rapid absorption as soon as a myocardial infarction is suspected. The same dose should be given as maintenance over the next 30 days. After 30 days, consider further therapy based on dosage and administration for prevention of recurrent MI (see Prior Myocardial Infarction below).
Prevention of a First Non-fatal Myocardial Infarction: 80-325 mg once daily, according to the individual needs of the patient, as determined by the physician.
Prior Myocardial Infarction or Unstable Angina Pectoris: 80-325 mg daily according to the individual needs of the patient, as determined by the physician.
Transient Ischemic Attack (TIA) and Secondary Prevention of Atherothrombotic Cerebral Infarction: 80-325 mg daily according to the individual needs of the patient, as determined by the physician.
Prophylaxis of Venous Thromboembolism after Total Hip Replacement: 650 mg twice a day (1300 mg daily), started 1 day before surgery and continued for 14 days.
