BAYER ASPIRIN Aspirin 300mg Tablet 1's
Indications/Uses
Dosage/Direction for Use
One tablet preferably taken after meals, with plenty of water.
Dosage regimen: Acute myocardial infarction: an initial dose of 162 to 325 mg is administered as soon as the myocardial infarction is suspected. The maintenance dose of 162 mg to 325 mg every day is continued for 30 days post-infarction. After 30 days, consider further therapy for prevention of recurrent myocardial infarction. The initial dose of all tablet formulations, including gastro-resistant tablets, used for this indication should be crushed or chewed and swallowed in order to achieve fast absorption.
Previous myocardial infarction: 81 to 325 mg per day.
Secondary prevention of stroke: 81 to 325 mg per day.
In patients with TIA: 81 to 325 mg per day.
In patients with stable and unstable angina pectoris: 81 to 325 mg per day.
Prevention of thromboembolism after vascular surgery or interventions: 81 to 325 mg per day.
Prophylaxis of deep vein thrombosis and lung embolism: 81 to 200 mg per day or 300 to 325 mg every other day.
Reducing the risk of first myocardial infarction: 81 to 100 mg per day or 300 to 325 mg every other day.
Additional information on special populations: Patients with hepatic impairment: Aspirin is contraindicated in patients with severe hepatic failure (see Contraindications). Aspirin should be used with particular caution in patients with impaired hepatic function (see Precautions).
Patients with renal impairment: Aspirin is contraindicated in patients with severe renal failure (see Contraindications). Aspirin should be used with particular caution in patients with impaired renal function since Aspirin may further increase the risk of renal impairment and acute renal failure (see Precautions).
Overdosage
Chronic salicylate poisoning can be insidious as signs and symptoms are non-specific. Mild chronic salicylate intoxication, or salicylism, usually occurs only after repeated use of large doses. Symptoms include dizziness, vertigo, tinnitus, deafness, sweating, nausea and vomiting, headache, and confusion, and may be controlled by reducing the dosage. Tinnitus can occur at plasma concentrations of 150 to 300 micrograms/mL. More serious adverse events occur at concentrations above 300 micrograms/mL.
The principle feature of acute intoxication is severe disturbance of the acid-base balance, which may vary with age and severity of intoxication. The most common presentation for a child is metabolic acidosis. The severity of poisoning cannot be estimated from plasma concentration alone. Absorption of Aspirin can be delayed due to reduced gastric emptying, formation of concretions in the stomach, or as a result of ingestion of gastroresistant preparations. Management of Aspirin intoxication is determined by its extent, stage and clinical symptoms and according standard poisoning management techniques. Predominant measures should be the accelerated excretion of the drug as well as the restoration of the electrolyte and acid-base metabolism.
Due to the complex pathophysiologic effects of salicylate poisoning, signs and symptoms/investigational findings may include: See Table 1.
Administration
Contraindications
Special Precautions
History of gastro-intestinal ulcers including chronic or recurrent ulcer disease or history of gastro-intestinal bleedings.
With concomitant treatment with anticoagulants (see Interactions).
In patients with impaired renal function or patients with impaired cardiovascular circulation (e.g. renal vascular disease, congestive heart failure, volume depletion, major surgery, sepsis or major hemorrhagic events), since Aspirin may further increase the risk of renal impairment and acute renal failure.
In patients suffering from severe glucose-6-phosphate dehydrogenase (G6PD) deficiency, Aspirin may induce hemolysis or hemolytic anemia. Factors that may increase the risk of hemolysis are e.g. high dosage, fever or acute infections.
Impaired hepatic function.
Some NSAIDs, such as ibuprofen and naproxen, may attenuate Aspirin's inhibitory effect on platelet aggregation. Patients should be advised to talk to their doctor if they are on an Aspirin regimen and plan to take NSAIDs (see Interactions).
Aspirin may precipitate bronchospasm and induce asthma attacks or other hypersensitivity reactions. Risk factors are pre-existing asthma, hay fever, nasal polyps, or chronic respiratory disease. This also applies to patients exhibiting allergic reactions (e.g., cutaneous reactions, itching, urticaria) to other substances.
Aspirin may precipitate bronchospasm and induce asthma attacks or other hypersensitivity reactions. Risk factors are pre-existing asthma, hay fever, nasal polyps, or chronic respiratory disease. This also applies to patients exhibiting allergic reactions (e.g., cutaneous reactions, itching, urticaria) to other substances.
Due to its inhibitory effect on platelet aggregation which persists for several days after administration, Aspirin may lead to an increased bleeding tendency during and after surgical operations (including minor surgeries, e.g., dental extractions).
At low doses, Aspirin reduces the excretion of uric acid. This can possibly trigger gout attacks in predisposed patients.
Aspirin containing products should not be used in children and adolescents 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.
Use In Pregnancy & Lactation
Animal studies have shown reproductive toxicity.
During the first and second trimester of pregnancy, acetyl salicylic acid containing drugs should not be given unless clearly necessary. If acetyl salicylic acid containing drugs are used by a woman attempting to conceive, or during the first and second trimester of pregnancy, the dose should be kept as low and duration of treatment as short as possible.
During the third trimester of pregnancy, all prostaglandin synthesis inhibitors may expose the fetus to: cardiopulmonary toxicity (with premature closure of the ductus arteriosus and pulmonary hypertension); renal dysfunction, which may progress to renal failure with oligo-hydroamniosis; the mother and the child, at the end of pregnancy, to: possible prolongation of bleeding time, an anti-aggregating effect which may occur even after very low doses; inhibition of uterine contractions resulting in delayed or prolonged labour.
Consequently, Aspirin is contraindicated during the third trimester of pregnancy.
Lactation: Salicylates and its metabolites pass into breast milk in small quantities.
Since no adverse effects on the infant have been observed so far 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.
Adverse Reactions
Tabulated list of adverse reactions: See Table 2.
Drug Interactions
Combinations requiring precautions for use: Methotrexate, used at doses of less than 15 mg/week: Increased hematological toxicity of methotrexate (decreased renal clearance of methotrexate by anti inflammatory agents in general and displacement of methotrexate from its plasma protein binding by salicylates).
NSAIDs: The concurrent (same day) administration of some NSAIDs, such as ibuprofen and naproxen, may attenuate the irreversible platelet inhibition induced by Aspirin. The clinical relevance of these interactions is not known. Treatment with some NSAIDS, such as ibuprofen or naproxen, in patients with increased cardiovascular risk may limit the cardiovascular protection of Aspirin (see Precautions).
Anticoagulants, thrombolytics/other inhibitors of platelet aggregation/hemostasis: Increased risk of bleeding.
Other non-steroidal anti-inflammatory drugs with salicylates at higher doses: Increased risk of ulcers and gastrointestinal bleeding due to synergistic effect.
Selective Serotonin Re-uptake Inhibitors (SSRIs): Increased risk of upper gastrointestinal bleeding due to possibly synergistic effect.
Digoxin: Plasma concentrations of digoxin are increased due to a decrease in renal excretion.
Antidiabetics, e.g. insulin, sulphonylureas: Increased hypoglycemic effect by high doses of Aspirin via hypoglycemic action of Aspirin and displacement of sulfonylurea from its plasma protein binding.
Diuretics in combination with Aspirin at higher doses: Decreased glomerular filtration via decreased renal prostaglandin synthesis.
Systemic glucocorticoids, 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.
Angiotensin converting enzyme inhibitors (ACE) in combination with Aspirin at higher doses: Decreased glomerular filtration via inhibition of vasodilatory prostaglandins. Further-more, decreased antihypertensive effect.
Valproic Acid: Increased toxicity of valproic acid due to displacement from protein binding sites.
Alcohol: Increased damage to gastro-intestinal mucosa and prolonged bleeding time due to additive effects of Aspirin and alcohol.
Uricosurics such as benzbromarone, probenecid: Decreased uricosuric effect (competition of renal tubular uric acid elimination).
Storage
Action
Pharmacology: Pharmacodynamics: Aspirin inhibits platelet aggregation by blocking thromboxane A2 synthesis in platelets. Its mechanism of action is based on irreversible inhibition of cyclo-oxygenase (COX-1). This inhibitory effect is especially pronounced in platelets, because platelets are unable to resynthesize this enzyme. Aspirin is also thought to have other inhibitory effects on platelets. Thus, it is used for various vascular indications.
Aspirin belongs to the group of acidic nonsteroidal anti-inflammatory drugs with analgesic, antipyretic and anti-inflammatory properties.
Higher oral doses are used for the relief of pain and in minor febrile conditions, such as colds or influenza, for the reduction of temperature and relief of the joint and muscle pains, and in acute and chronic inflammatory disorders such as rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis.
Pharmacokinetics: Absorption: Following oral administration, Aspirin is absorbed rapidly and completely from the gastro-intestinal tract. During and after absorption Aspirin is converted into its main active metabolite, salicylic acid. Maximal plasma levels are reached after 10 - 20 minutes for Aspirin and after 0.3-2 hours for salicylic acid, respectively.
Tablets (immediate-release): Cmax is reached after approximately 30 minutes for Aspirin and after 1.5 hours for salicylic acid, respectively, when administered under fasting conditions. Intake with food leads to comparable Cmax and AUC, but the time to Cmax is prolonged on average about 2.7-fold when taken together with food. However, due to the mechanistic relationship between the total plasma exposure of Aspirin and its inhibitory effect on platelet aggregation, the difference in the rate of absorption of Aspirin is not considered relevant for the chronic therapy with low dose Aspirin in order to accomplish adequate inhibition of platelet aggregation.
Distribution: Both Aspirin and salicylic acid are extensively bound to plasma proteins and are rapidly distributed throughout the body. Salicylic acid passes into breast milk and crosses the placenta (see Use in Pregnancy & Lactation).
Metabolism/Biotransformation: The parent drug Aspirin is converted into its main metabolite salicylic acid. The acetyl group of Aspirin begins to split off hydrolytically even during passage through the intestinal mucosa but mainly this process takes place in the liver. The main metabolite Salicylic acid is eliminated predominantly by hepatic metabolism. Its metabolites are salicyluric acid, salicylic phenolic glucuronide, salicylacyl glucuronide, gentisic acid, and gentisuric acid.
Elimination/Excretion/Linearity: The elimination kinetics of salicylic acid is dose-dependent, as metabolism is limited by liver enzyme capacity. The elimination half-life therefore varies from 2 to 3 hours after low doses to up to about 15 hours at high doses. Salicylic acid and its metabolites are excreted mainly via the kidneys. Available pharmacokinetic data of Aspirin do not indicate a clinical meaningful deviation from dose-proportionality in the dose range of 100 mg to 500 mg.
MedsGo Class
Features
- Aspirin