This information is intended for use by health professionals
Aspirin 300mg Gastro-resistant Tablets
Postmi 300mg Gastro-resistant Tablets
Each tablet contains 300mg Aspirin EP
Aspirin 300mg Tablets contain an anti-pyretic, anti inflammatory and analgesic, and are gastro-resistant to reduce the gastric side-effects of aspirin in rheumatoid arthritis and in conditions requiring continued management with aspirin.
Aspirin may be used to reduce the risk of myocardial infarction in patients with unstable angina or in patients with a previous history of myocardial infarction.
For oral administration.
Analgesic, anti inflammatory, anti-pyretic;
Adults (including the elderly) and children over 16 years:
3 tablets (900mg) 3-4 times daily as required, at least 4 hours apart. Do not give to children under 16 years, unless specifically indicated (e.g. for Kawasaki's disease).
Anti-thrombotic effect to reduce the risk of myocardial infarction:
One tablet daily.
Aspirin must not be chewed or crushed. The tablets are best taken before meals.
Aspirin should not be administered to patients:
• with a history of hypersensitivity to aspirin or any other NSAID;
• with active peptic ulceration or a history of peptic ulceration;
• with haemophilia and other bleeding disorders;
• for the treatment of gout;
• who are breastfeeding.
Aspirin should be used with caution in patients with asthma or allergic disorders.
Caution should also be exercised in patients with:
• hepatic impairment;
• renal impairment;
• uncontrolled hypertension.
High doses of aspirin may precipitate acute haemolytic anaemia in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency.
Aspirin should be used with caution in the elderly because of the risk of serious side effects.
There is a possible association between aspirin and Reye's Syndrome when given to children. Reye's Syndrome is a very rare disease which affects the brain and liver and can be fatal. For this reason it should not be given to children under 16, unless specifically indicated (e.g. for Kawasaki's disease).
Concomitant use of aspirin with mifepristone should be avoided, because of a theoretical risk that prostaglandin synthetase inhibitors may decrease the efficacy of mifepristone.
Experimental data suggest that ibuprofen may inhibit the effect of low dose aspirin on platelet aggregation when they are dosed concomitantly. However, the limitations of these data and the uncertainties regarding extrapolation of ex vivo
data to the clinical situation imply that no firm conclusions can be made for regular ibuprofen use, and no clinically relevant effect is considered to be likely for occasional ibuprofen use (see section 5.1).
Concomitant use of aspirin with NSAIDs or corticosteroids may increase the likelihood of GI side effects. The antiplatelet effect of aspirin may be reduced by ibuprofen.
The rate of absorption of aspirin is increased by metoclopramide. The rate of absorption of aspirin is reduced by adsorbants e.g. kaolin.
The excretion of aspirin may be increased by alkaline urine, which can occur with some antacids.
Concommitant use of anticoagulants e.g. coumarins, phenindione, heparins; antidepressants e.g. SSRIs or venlafaxine; clopidogrel, iloprost and sibutramine with aspirin may lead to an increased risk of bleeding.
Aspirin enhances the effects of antiepileptics e.g. phenytoin and valproate.
There is a risk of renal impairment when aspirin (in doses over 300mg daily) is given with ACE inhibitors or angiotensin-II receptor antagonists and the hypotensive effect of these drugs is antagonised.
Co-administration of aspirin with zafirlukast may result in increased plasma concentration of zafirlukast.
Aspirin may reduce the effectiveness of spironolactone and inhibit the action of uricosurics e.g. probenecid and sulfinpyrazone when administered concurrently with these drugs.
The toxicity of methotrexate and carbonic anhydrase inhibitors may be increased when administered concurrently with aspirin.
Short term (≤ 4 days) co-administration of aspirin with cilostazol suggested a 23-25% increase in inhibition of ADP-induced ex vivo
platelet aggregation when compared to aspirin alone. Therefore it is recommended that the daily dose of aspirin should not exceed 80mg.
Although clinical and epidemiological evidence suggests the safety of aspirin for use in pregnancy, caution should be exercised when administered to pregnant patients.
Aspirin has the ability to alter platelet function and, therefore, there may be a risk of haemorrhage in infants whose mothers have consumed aspirin during pregnancy. The onset of labour may be delayed and the duration increased, with an increase in maternal blood loss. Therefore, analgesic doses should be avoided during the last trimester of pregnancy.
High doses of aspirin may result in closure of foetal ductus arteriosus in utero and possibly persistent pulmonary hypertension in the new born. Kenicterus may be a consequence of jaundice in neonates.
Administration of aspirin at doses greater than 300 mg/day, shortly before birth, can lead to intra-cranial haemorrhage, particularly in premature babies.
Lactation (see section 4.3)
The intake of aspirin by breast-feeding patients is contraindicated as there is a risk of Reye's syndrome. Regular use of high doses could impair platelet function and produce hypoprothrombinaemia in the infant if neonatal vitamin K stores are low.
Generally mild and infrequent but high incidence of gastro-intestinal irritation with slight asymptomatic blood loss, increased bleeding time, bronchospasm and skin reactions in hypersensitive patients. Gastro-intestinal haemorrhage (occasionally major) also other haemorrhage (e.g. subjunctival).
Other undesirable effects common with anti-inflammatory doses; gastrointestinal discomfort or nausea, ulceration with occult bleeding (but occasionally major haemorrhage); hearing disturbances such as tinnitus (leading rarely to deafness), vertigo, confusion, rarely oedema and blood disorders, particularly thrombocytopenia.
Salicylate poisoning is usually associated with plasma concentrations>350 mg/L (2.5 mmol/L). Most adult deaths occur in patients whose concentrations exceed 700 mg/L (5.1 mmol/L). Single doses less than 100 mg/kg are unlikely to cause serious poisoning.
Common features include vomiting, dehydration, tinnitus, vertigo, deafness, sweating, warm extremities with bounding pulses, increased respiratory rate and hyperventilation. Some degree of acid-base disturbance is present in most cases.
A mixed respiratory alkalosis and metabolic acidosis with normal or high arterial pH (normal or reduced hydrogen ion concentration) is usual in adults and children over the age of four years. In children aged four years or less, a dominant metabolic acidosis with low arterial pH (raised hydrogen ion concentration) is common. Acidosis may increase salicylate transfer across the blood brain barrier.
Uncommon features include haematemesis, hyperpyrexia, hypoglycaemia, hypokalaemia, thrombocytopaenia, increased INR/PTR, intravascular coagulation, renal failure and non-cardiac pulmonary oedema.
Central nervous system features including confusion, disorientation, coma and convulsions are less common in adults than in children.
Give activated charcoal if an adult presents within one hour of ingestion of more than 250 mg/kg. The plasma salicylate concentration should be measured, although the severity of poisoning cannot be determined from this alone and the clinical and biochemical features must be taken into account. Elimination is increased by urinary alkalinisation, which is achieved by the administration of 1.26% sodium bicarbonate. The urine pH should be monitored. Correct metabolic acidosis with intravenous 8.4% sodium bicarbonate (first check serum potassium). Forced diuresis should not be used since it does not enhance salicylate excretion and may cause pulmonary oedema.
Haemodialysis is the treatment of choice for severe poisoning and should be considered in patients with plasma salicylate concentrations>700 mg/L (5.1 mmol/L), or lower concentrations associated with severe clinical or metabolic features. Patients under ten years or over 70 have increased risk of salicylate toxicity and may require dialysis at an earlier stage.
Aspirin has analgesic, anti-inflammatory, anti-pyretic and uricosuric actions.
It is used for the relief of the less severe types of pain such as headache, neuritis, acute and chronic rheumatoid arthritis, myalgias and toothache.
Gastro-resistant tablets may be used with the intention of minimising gastric irritation. In the treatment of minor febrile conditions, such as colds or influenza, aspirin is of value for the reduction of temperature and relief of the headache and the joint and muscle pains.
As an anti-pyretic, aspirin, like many related drugs, acts on the heat-regulating centres in the brain to bring about a dissipation of body heat through cutaneous vasodilatation. The usual dose of aspirin as an analgesic and anti-pyretic is 0.3 to 1g which may be repeated according to clinical needs, up to a maximum of 4g daily.
Aspirin is used in the treatment of acute and chronic rheumatic states. Maximum suppression of rheumatic symptoms occurs with plasma concentrations of about 300 µg/ml, but these concentrations are frequently associated with mild toxic effects such as nausea and tinnitus; adequate control of rheumatic symptoms may often be achieved with lower concentrations. In chronic rheumatic disease, 300 to 900mg is administered every 4 hours over long periods. In acute rheumatism, 4 to 8g daily in divided doses is sometimes recommended, but doses of 150mg/kg body-weight daily have been given initially.
Experimental data suggest that ibuprofen may inhibit the effect of low dose aspirin on platelet aggregation when they are dosed concomitantly. In one study, when a single dose of ibuprofen 400mg was taken within 8 hours before or within 30 minutes after immediate release aspirin (81mg), a decreased effect of aspirin on the formation of thromboxane or platelet aggregation occurred. However, the limitations of these data and the uncertainties regarding extrapolation of ex vivo
data to the clinical situation imply that no firm conclusions can be made for regular ibuprofen use, and no clinically relevant effect is considered to be likely for occasional ibuprofen use.
Absorption of non-ionised aspirin occurs in the stomach. Acetylsalicylates and salicylates are also readily absorbed from the intestine. Hydrolysis to salicylic acid occurs rapidly in the intestine and in the circulation. Salicylates are extensively bound to Plasma proteins, aspirin to a lesser degree. Aspirin and salicylates are rapidly distributed to all body tissues; they appear in milk and cross the placenta. The rate of excretion of aspirin varies with the pH of the urine, increasing as the pH rises and being greatest at pH 7.5 and above.
A circadian excretion rhythm has been reported. Aspirin is excreted as salicylic acid and as glucuronide conjugates and as salicylic and gentisic acids.
Microcrystalline Cellulose, Methacrylic Acid Copolymer, Talc, Maize Starch, Silica, Triethyl Citrate, Zinc Stearate, Sodium Hydroxide, Polyethylene Glycol 6000, Shellac, propylene glycol, Titanium Dioxide (E171) and Iron Oxide (E172).
Polypropylene and polyethylene containers (Tracer packs): pack sizes 25, 28, 30, 50, 84, 100.
Polypropylene containers (Securitainers): pack size 1000.
Focus Pharmaceuticals Limited
Unit 5, Faraday Court,
First Avenue, Centrum 100,
Burton upon Trent