Aspirin

Aspirin is a salicylate NSAID (non-steroidal anti-inflammatory drug). It has analgesic, anti-inflammatory and antipyretic properties. It is used for the relief of mild to moderate pain such as headache, dysmenorrhoea, myalgias and dental pain. In the treatment of minor febrile conditions, such as colds or influenza, aspirin can reduce temperature and relieve headache and joint and muscle pains. Aspirin is also used for its antiplatelet activity in the initial treatment of cardiovascular disorders such as myocardial infarction and for the prevention of ischaemic stroke in patients at risk.

Pronunciation

Aspirin 100mg + Glycine 45mg

Aspirin 80mg

Aspirin enteric-coated 100mg

Drug Names

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Paracetamol Tablet 500mg	PARA01	Panadol

Mechanism of Action

Pain relief Anticoagulation therpay Anti-inflammatory effect Non-opioid Analgesic (NSAID) Anti-inflammatory agent Anticoagulant

Dosage

See Anticoagulant

As an analgesic and antipyretic:

Oral	300 to 900 mg, repeated every 4 to 6 hours, to a max of 3.6 g daily.

Indications for aspirin therapy in children is limited because of the risk of Reye’s syndrome. Mild to moderate pain: 300-900 mg q4-6h PRN, max 4g.

Side Effects

The most common adverse effects are gastrointestinal disturbances such as nausea, dyspepsia and vomiting.

Gastrointestinal symptoms may be minimized by giving aspirin with food.

Some persons, especially those with asthma, chronic urticaria, or chronic rhinitis, exhibit hypersensitivity to aspirin, which may provoke reactions including urticaria and other skin eruptions, rhinitis and severe, even fatal, paroxysmal bronchospasm and dyspnoea. Persons sensitive to aspirin often have cross-sensitivity to other NSAIDs.

Stomach pain, heartburn, Stomach ulcers Liver or kidney problems.

High blood pressure

Pharmacokinetics

Aspirin is absorbed rapidly from the gastrointestinal tract when taken orally but absorption after rectal doses is less reliable. Aspirin is 80 to 90% bound to plasma proteins and is widely distributed. The plasma-salicylate half-life is about 2 to 3 hours.

It crosses the placenta and distributes into breast milk.

Drug Management=

Precautions

• In patients prone to dyspepsia or known to have a lesion of the gastric mucosa
• Should not be given to patients with haemophilia or other haemorrhagic disorders
• Not to treat patients with gout (since low doses increase urate concentrations)
• In patients with asthma
• Should be avoided in severe renal and hepatic impairment
• Should be stopped several days before scheduled surgical procedures.