Drug Interaction:
Potentially Hazardous Interaction:
Effects of oral anticoagulants, methotrexate, oral hypogly-caemics, potentiated. Increased risk of peptic ulceration due to alcohol,corticosteroids, analgin, NSAID's. Aspirin levels increased by metoclopramide and reduced by phenobarbitone, urinary alkalisers. Aminophyline may reduce vasodilator effect of dypyridamol, antacids reduce efficay. Aspirin may antagonise effects of uricosurics, spironolactone.
Adverse Reaction:
Potentially Life Threatening Reaction: Gastric erosion, bleeding. Fatal exacerbation of airways obstruction, cerbral haemorrhage in patients with pre-existing vascular lesion.
GI disturbances, epigastric discomfort, rhinitis, urticaria, prolonged bleeding time, headache, dizziness, facial flushing, faintness, skin rash.
Contra-Indications:
Contraindication: Hypersensitivity, peptic ulcer, coagulation disorders, Children under 12.
Special Precaution:
Unstable angina,recent MI,subaortic stenosis,history of peptic ulcer,bronchospasm,history of NSAID/Aspirin-induced allergy,pregnancy,lactation.
Coagulation disoders, Myastthenia gravis, anprin/anti-inflammatory drugs, allegic rhinitis, nasal polops, history of GI upset G-6 PD deficiency
Other Information:
EVIDENCE BASED MEDICINE (April 2003)
Stroke prevention Comparative effectiveness of various interventions
PRIOR TO STROKE OR TRANSIENT ISCHAEMIC ACCIDENT (TIA)
Beneficial
1. Antiplatelet treatment
2. Cholestrerol reduction (for those patients who also have coronary heart disease)
3. Carotid endarterectomy (in patients with severe symptomatic carotid artery stenosis)
Unknown effectiveness
1. Cholesterol reduction (for patients without CHD)
2. Blood pressure reduction
3. Carotid endarterectomy (in patients with severe symptomatic carotid artery stenosis)
4. Catotid angioplasty
Likely to ineffective or even harmful
1. Oral anticoagulation ATRIAL FIBRILLATION AND A PRIOR STROKE OR TIA
Beneficial
1. Oral anticoagulation
2. Aspirin for patients with contraindications to an anticoagulant
ATRIAL FIBRILLATION BUT NO OTHER MAJOR RISK FACTORS FOR STROKE
Likely to be beneficial
1. Oral anticoagulation
2. Aspirin for patients with contraindications to an anticoagulant
KEY POINTS
In patients with a prior stroke or TIA
1. Insufficient evidence to support routine blood presure reduction
2. Statins may prevent stroke in those with a history of CHD but evidence inconclusive in those with no history of CHD.
3. Routine use of prolonged anti-platelet treatment beneficial ( if no contraindication)
4. Aspirin 75mg daily as effective as higher doses. No evidence that any other antiplatelet regimen is definitely superior in the prevention of vascular events. Clopidogrel or the combination of asprin and dipyridamole are safe and effective (but more costly) alternatives to aspirin
5. No evidence of benefit from anti-coagulation in patients in sinus rhythm, but an increased risk of serious bleeding
6. Carotid endarterectomy reduces risk of major stroke in patients with severe carotid stenosis provided the risks of imaging and surgery are small.
7. Percutaneous transluminal angioplastys role has not been evaluated adequately In patients with atrial fibrillation and a pror stroke or TIA
1. Anticoagulants reduce risk of stroke, provided there is low risk of bleeding and careful monitoring
2. Aspirin reduces risk of stroke but less effectively than anticoagulants. These findings support the use of aspirin among patients with atrial fibrillation and contra-indication to anticoagulants In patients with atrial fibrillation but neither major risk factors for stroke
1. Anticoagulants are of net benefit, if low risk of bleeding and careful monitoring
2. Aspirin is a reasonable alternative in patients with contra-indications to anticoagulants
