Aspirin

Anticoagulant/Antiplatelet · Salicylate

Indications

Prevention of secondary thrombotic cerebrovascular or cardiovascular disease and following surgery. Mild to moderate pain. COVID-19.

Dosage

Stroke/TIA: Adults: 50-325 mg once daily. Suspected AMI: Adults: Initial: 160-162.5 mg once daily as soon as suspect MI. Maintenance: 160-162.5 mg for 30 days post-infarction. Prevention or Recurrent MI: Adults: 75-325 mg once daily. Pain: Adults & Children: Above 12 yr age: 325-1000 mg every 4-6 hr as needed. Max: 4 gm/day. COVID-19: 100 mg/day orally with combined standard treatment.

Adverse Effects

Bronchospasm, GI upset, allergic reactions, GI and other haemorrhage. Tinnitus, vertigo, confusion, increased bleeding.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Positive evidence of risk: Use only when no safer alternative exists for a serious problem. Lactation: Caution advised or effect undetermined. Contraindications: Previous or active peptic ulceration, haemophilia and other bleeding disorders. Severe renal or hepatic impairment Children under 16 years unless specifically indicated (e.g. for Kawasaki's disease). Precautions: Aspirin/anti-inflammatory induced allergies, history of bronchospasm, asthma, uncontrolled hypertension, mild to moderate renal function, renal or hepatic impairment, dehydration, G6PD deficiency. Not recommended for treatment of gout. Elderly; avoid continuous prolonged use.

Interactions

Oral anticoagulants, heparin, antiplatelet agents, fibrinolytics, NSAIDs, uricosuric agents, methotrexate, SSRls, venlafaxine, corticosteroids, acetazolamide, tacrolimus, ciclosporin, antihypertensives.

Advice to Patient

Take with meals or large volume of water or milk. Do not chew or crush tablets, swallow whole. Stop taking aspirin and contact prescriber if there is ringing in ears, persistent stomach pain, unresolved nausea or vomiting, respiratory difficulty or shortness of breath, unusual bruising or bleeding (mouth, urine, stool) or skin rash. Do not use if aspirin has strong vinegar-like odour. Avoid alcohol, high amounts of vitamin C, salicylate-containing foods (for example, curry powder, prunes, raisins, tea or licorice), OTC and other prescription medications containing aspirin or salicylate and other NSAIDS. Maintain hydration by taking 2-3 litres of fluid per day unless restricted by prescriber. Do not take if there is tartrazine allergy.

Pharmacokinetics

Onset: Immediate release: Platelet inhibition: Within 1 hr (nonenteric-coated). Onset of enteric-coated aspirin expected to be delayed. Duration: Immediate release: 4-6 hrs. Absorption: Immediate release: Rapidly absorbed in stomach and upper intestine. Extended release capsule: Rate of absorption depends upon food, alcohol and gastric pH. Metabolism: Via esterases in GI mucosa, RBCs, synovial fluid and blood. Salicylate: Via hepatic conjugation. Bioavailability: Immediate release: 50%-75%. Half-life elimination: Parent drug: Plasma conc: 15-20 min. Salicylates (dose dependant): 3 hrs at lower doses (300-600 mg), 5-6 hrs (after 1 gm), 10 hrs with higher doses). Time to peak, serum: Immediate release: Approx 1-2 hrs (nonenteric-coated), 3-4 hrs (enteric-coated). Extended release capsule: Approx. 2 hrs. Excretion: Urine.

Unlicensed Use

Not licensed for use in children under 16 yr. Children: Kawasaki disease: Neonate, initially 8 mg/kg 4 times daily for 2 wk or until afebrile, followed by 5 mg/kg once daily for 6-8 wk; if no evidence of coronary lesions after 8 wk, discontinue treatment or seek expert advice. 1 mth-12 yr, initially 7.5-12.5 mg/kg 4 times daily for 2 wk or until afebrile, then 2-5 mg/kg once daily for 6-8 wk; if no evidence of coronary lesions after 8 wk, discontinue treatment or seek expert advice. Antiplatelet, prevention of thrombus formation after cardiac surgery: Neonate, 1-5 mg/kg once daily; 1 mth-12 yr, 1-5 mg/kg (max 75 mg) once daily; 12-18 yr, 75mg once daily.

Brands with this active ingredient

Compiled by Healify Pharmacy from published drug references. How we compile it →

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