Clinical Pharmacology Details


ASPIRIN (ACETYLSALICYLIC ACID)


View Drug Forms

Indications & Dose:

Cardiovascular disease (secondary prevention) l



Adult: 75 mg daily


Management of unstable angina and non-ST-segment elevation myocardial infarction (NSTEMI) | Management of ST-segment elevation myocardial infarction (STEMI)



Adult: 300 mg, chewed or dispersed in water


Suspected transient ischaemic attack l



Adult: 300 mg once daily until diagnosis established


Transient ischaemic attack (long-term treatment in combination with dipyridamole) | Ischaemic stroke not associated with atrial fibrillation (in combination with dipyridamole if clopidogrel contra-indicated or not tolerated) Ischaemic stroke not associated with atrial fibrillation (used alone if clopidogrel and dipyridamole contra-indicated or not tolerated)



Adult: 75 mg once daily


Acute ischaemic stroke



Adult: 300 mg once daily for 14 days, to be initiated 24 hours after thrombolysis or as soon as possible within 48 hours of symptom onset in patients not receiving thrombolysis


Atrial fibrillation following a disabling ischaemic stroke(before being considered for anticoagulant treatment)



Adult: 300 mg once daily for 14 days


Following disabling ischaemic stroke in patients receiving anticoagulation for a prosthetic heart valve and who are at significant risk of haemorrhagic transformation



Adult: 300 mg once daily, anticoagulant treatment stopped for 7 days and to be substituted with aspirin


Following coronary by-pass surgery l



Adult: 75–300 mg daily


Mild to moderate pain


Pyrexia



Adult: 300–900 mg every 4–6 hours as required;maximum 4 g per day



Adult: 450–900 mg every 4 hours; maximum 3.6 g per day.


 


 

Contraindications:

Hypersensitivity to salicylates, NSAIDs, or tartrazine GI bleeding; hemophilia; hemorrhagic states 

Side Effects:

CNS: Confusion, dizziness, drowsiness, headache


EENT: Dimness of vision, reversible hearing loss, tinnitus


GI: Acute reversible hepatotoxicity, anorexia, cholestasis, diarrhea, dyspepsia, epigastric discomfort, GI bleeding, heartburn, increased transaminase levels, nausea


HEMS: Decreased plasma iron concentration, hyperuricemia (low dose), hyperuricosuria (high dose), leukopenia, prolonged bleeding time, shortened erythrocyte survival time, thrombocytopenia


METAB: Hypoglycemia, hypokalemia, hyponatremia


RESP: Hyperpnea, wheezing


SKIN: Angioedema, bruising, hives, rash, urticaria


MISC: Fever, thirst


 

Cautions:

Precautions:

Anemia, asthma, nasal polyps, nasal allergies, hepatic disease, renal disease, Hodgkin’s disease, pre/postoperatively, children or teenagers with flu-like symptoms (may be associated with the development of Reye’s syndrome), gout, history of coagulation defects, bleeding disorders


PREGNANCY; ( if full doses used in 3rd trimester); use in pregnancy should generally be avoided; in pregnancies at risk for the development of pregnancy inducedhypertension and preeclampsia, and in fetuses with- intrauterine growth retardation, low dose aspirin (40-150 mg/day) may be beneficial; excreted into breast milk in low concentrations


 

Interaction:

Drugs


ACE inhibitors: Reduced anti hypertensive effect


Acetazolamide: Increased concentrations of acetazolamide, possibly leading to CNS toxicity


Antacids: Decreased serum salicylate concentrations; high dog salicylates only


Corticosteroids: Increased incidence and/or severity of GI ulceration; enhanced salicylate excretion


Diltiazem: Enhanced antiplatelet effect of aspirin


Ethanol: Enhanced aspirin induced GI mucosal damage and aspirin induced prolongation of bleeding time


Griseofulvin: Reduced serum salicylate level


Intrauterine contraceptive device: May reduce contraceptive effectiveness


Methotrexate: Increased serum methotrexate concentrations and enhanced methotrexate toxicity


Oral anticoagulants: Increased risk of bleeding by inhibiting platelet function and possibly by producing gastric erosions


Probenecid: Salicylates inhibit the uricosuric activity of probenecid


Sulfinpyrazone: Salicylates inhibit the uricosuric activity of sulfinpyrazone


Sulfonylurea: Enhanced hypoglycemic response to sulfonylurea


Warfarin: Enhanced hypoprothrombinemic effect of warfarin


Zarfirlukast: Increased plasma concentrations of zarfirlukast


 

Warnings:

Adverse Effects:

Lactations:

Special Precautions:

Counselling:

Side Effects Or Adverse Reactions:

Patient And Carer Advice: