Aspirin

Aspirin

Is a non opioid analgesic. GSL, P, POM

Conditions drugs used for

Mild to moderate pain Pyrexia (raised body

temperature or fever)

Anti-platelet

Dose

For pain and pyrexia 300-900mg every 4-6 hours when necessary, max 4g daily. Anti-platelet 75-300mg daily

How drug works

Reduces the production of prostaglandins

Prevents blood clots forming.

Reduces stickiness of platelets.

Side-effects

Mild and infrequent but high incidence of gastro-intestinal irritation with slight asymptomatic blood loss.

Dyspepsia, abdominal pain, diarrhoea, bleeding disorders.

Important

Analgesics: Avoid concomitant use of aspirin with Non-Steroidal

Anti-inflammatory drugs (NSAIDS)

 Anticoagulants: Increased risk of bleedings when aspirin given

with coumarins or phenidione. Aspirin enhances anti-coagulant

effect of heparins

 Antidepressants: Increased risk of bleeding when aspirin given

with SSRIs or Venlafaxine

 Cytotoxics: Aspirin reduces excretion of methotrexate

Important disease

interactions

(Contraindications and

Cautions)

Cautions- Asthma, uncontrolled hypertension, previous peptic

ulceration, concomitant use of drugs that increase risk of bleeding,

G6PD deficiency, dehydration and the elderly .Use with caution in

renal impairment- avoid in severe impairment

Contraindications - In those under 16 years, advice, active peptic

ulceration, haemophilia and other bleeding disorders

Avoid in severe hepatic impairment- increased risk of GI bleeding

Pregnancy: Avoid - especially in the third trimester. Risk of

haemorrhage, delayed labour with increased bleeding, in-uterine

closure of the ductus arteriosus, and pulmonary hypertension and

jaundice in new born infants

Breast Feeding: Avoid due to risk of Reyes Syndrome