Chemical Structure:
Class of drug:
- Non-steroidal anti-inflammatory drug (NSAID)
- Antiplatelet drug
Drug action/mode of action:
It works by inhibiting the enzyme cyclooxygenase (COX) thereby inhibiting the conversion of arachidonic acid into thromboxane, prostacyclin and prostaglandins. Read more here.
Medicinal forms:
Tablet, Dispersible tablet, Gastro-resistant tablets, Suppository.
Some brands available:
Nu-Seals, Alka-Seltzer, Danamep, Aggrenox, Anacin, Excedrin, Ecotrin, Bufferin, Aspirin (Wockhardt UK), Disprin, Numark Aspirin.
Indications and dose:
1. Cardiovascular disease (secondary prevention)
Adult: 75 mg daily.
2. Secondary prevention of deep-vein thrombosis and pulmonary embolism
Adult: 75 mg daily, alternatively 150 mg daily.
3. Management of unstable angina, ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI)
Adult: 300 mg, chewed or dispersed in water.
4. Suspected transient ischaemic attack
Adult: 300 mg once daily until diagnosis is established.
5. Ischaemic stroke not associated with atrial fibrillation
Adult: 75 mg once daily.
6. 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.
7. Mild to moderate pain and Pyrexia
Adult: 300-900 mg every 4-6 hours as required; maximum 4 g per day.
(By rectum) 450-900 mg every 4 hours; maximum 3.6 g per day.
Child 16–17 years: 300-600 mg every 4-6 hours as required, maximum 2.4 g per day
8. Acute migraine
Adult: 900 mg for 1 dose, to be taken as soon as migraine symptoms develop.
Unlicensed use:
Not licensed for use in children under 16 years
Contra-indications:
Active peptic ulceration; bleeding disorders; children under 16 years (risk of Reye’s syndrome); haemophilia; previous peptic ulceration (analgesic dose); severe cardiac failure (analgesic dose)
Cautions:
Allergic disease; anaemia; asthma; dehydration; elderly; G6PD deficiency; hypertension; may mask symptoms of infection; preferably avoid during fever or viral infection in children (risk of Reye’s syndrome); thyrotoxicosis
Interactions:
Acetazolamide – risk of severe toxic reaction
Apixaban – risk of bleeding
Bendroflumethiazide – risk of acute renal failure
Chlorothiazide – risk of acute renal failure
Chlortalidone – risk of acute renal failure
Dabigatran – risk of bleeding
Enoxaparin – risk of bleeding
Heparin – risk of bleeding
Hydrochlorothiazide – risk of acute renal failure
Indapamide – risk of acute renal failure
Methotrexate – Increased risk of toxicity
Metolazone – risk of acute renal failure
Nicorandil – risk of gastrointestinal perforation
Warfarin – risk of bleeding
Zidovudine – risk of haematological toxicity
Side-effects:
Common or very common (With oral use)
Dyspepsia; haemorrhage
Uncommon (With oral use)
Dyspnoea; rhinitis; severe cutaneous adverse reactions; skin reactions
Rare or very rare (With oral use)
Asthmatic attack; bronchospasm; aplastic anaemia; erythema nodosum; gastrointestinal haemorrhage (severe); granulocytosis; haemorrhagic vasculitis; intracranial haemorrhage; menorrhagia; nausea; thrombocytopenia; vomiting
Frequency not known (With oral use)
Fluid retention; gastrointestinal disorders; headache; hearing loss; hepatic failure; hyperuricaemia; iron deficiency anaemia; renal impairment; sodium retention; tinnitus; vertigo
Pregnancy:
Use antiplatelet doses with caution during third trimester; avoid analgesic doses if possible in last few weeks to delivery.
Breast feeding:
Avoid due to possible risk of Reye’s syndrome.
Hepatic impairment:
Use with caution in mild-to-moderate impairment; avoid in severe impairment.
Renal impairment:
Use with caution; avoid in severe impairment.
Other drugs in class:
Antiplatelet drugs
- Cangrelor
- Cilostazol
- Clopidogrel
- Dipyridamole
- Prasugrel
- Selexipag
- Ticagrelor
Non-steroidal anti-inflammatory drugs
- Aceclofenac
- Benzydamine hydrochloride
- Bromfenac
- Celecoxib
- Dexibuprofen
- Dexketoprofen
- Diclofenac potassium
- Diclofenac sodium
- Diclofenac sodium with misoprostol
- Etodolac
- Etoricoxib
- Felbinac
- Flurbiprofen
- Ibuprofen
- Indometacin
- Ketoprofen
- Ketorolac trometamol
- Mefenamic acid
- Meloxicam
- Nabumetone
- Naproxen
- Nepafenac
- Parecoxib
- Phenazone with lidocaine
- Piroxicam
- Sulindac
- Tenoxicam
- Tiaprofenic acid
- Tolfenamic acid
WRITTEN AND EDITED RESPECTIVELY BY:
MPSGH, MRPharmS, MPhil.
Isaiah Amoo is a practicing community pharmacist in good standing with the Pharmacy Council of Ghana who has meaningful experience in academia and industrial pharmacy. He is a member of the Royal Pharmaceutical Society, England, UK and currently pursuing his overseas pharmacy assessment programme (MSc) at Aston University, UK. He had his MPhil degree in Pharmaceutical Chemistry at Kwame Nkrumah University of Science and Technology. He has about 5 years’ experience as a community Pharmacist and has also taught in academic institutions like KNUST, Kumasi Technical University, Royal Ann College of Health, and G-Health Consult. He likes to spend time reading medical research articles and loves sharing his knowledge with others.
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