This code covers any products containing acetylsalicylic acid.
Salicylates are generally contraindicated during uricosuric therapy. Although large doses of salicylates (more than 5 or 6 grams daily) have uricosuric activity, smaller doses (less than 2 or 3 grams daily) of ASA will depress uric acid clearance and may induce hyperuricemia and gout. Salicylates also decrease the uricosuric effect of sulfinpyrazone and probenecid. There is data suggesting that these drugs decrease salicylate excretion, possibly leading to salicylate toxicity. Acetaminophen may be recommended.
ASA in large doses (more than 3 grams daily) is highly serum protein bound and displaces anticoagulant
(warfarin) from binding sites. This is most significant over short periods, as the prothrombin time will
return to normal with time. If a patient on blood thinners takes ASA, they should be counselled
to be sure to inform their doctor. This can be taken into consideration when testing prothrombin time.
Acetaminophen can be recommended for short term therapy.
Usual doses of ASA will inhibit platelet aggregation. The effect of ASA lasts for the life of the platelet (5 to 7 days). ASA should be discontinued 5 to 7 days before elective surgery because of the increased risk of bleeding. Acetaminophen can be recommended.
ASA is often implicated in childhood poisonings. Doses as low as 200 mg/kg of body weight can require treatment. This is as few as four enteric coated tablets for a small child. All salicylate preparations should be kept well out of the reach of children.
Reye's Syndrome is a rare but serious condition which occurs mainly in children and adolescents from 5 to 15
years of age and rarely in young adults. The mortality rate is very high at 22 to 42%. 1t typically occurs
in a child recovering frorn a viral illness such as the flu or chicken pox, with symptoms of persistent
and intractable vomiting, lethargy and confusion, irritability or aggressiveness. It is often viewed as a
relapse of the original illness, but can progress within minutes or hours to unconsciousness and coma. There
is evidence of a correlation with ingestion of salicylates (almost exclusively ASA) during the original viral
illness. Acetaminophen is the drug of choice for childhood pain and fever.
The pharmacist should be aware of the signs and symptoms ot Reye's syndrome since early detection can increase the chances of survival. If Reye's Syndrome is suspected, advise the parent to immediately contact their physician.
Phase 1. Persistent vomiting, lethargy, difficulty to stay awake. In the very young child, vomiting is rare; instead there is hyperventilation.
Phase 2: Confusion, disorientation; apathy or irritability; aggressiveness; hyperventilation; delirium, hyperreflexia, screaming.
Phase 3 Body rigidity; insensitivity to external stimuli; coma.
Phase 4: Rigidity; deep coma; decerebration; dilated pupils not responding to light.
Phase 5: Convulsions; fixed and dilated pupils; absence of tendon reflex; flaccid paralysis; cardio-respiratory insufficiency; death in 3 to 5 days if treatment is not successful.
ASA is contraindicated in patients with active peptic ulcer and erosive gastritis. Patients with active peptic ulcer, ulcerative colitis or upper Gl disease should not self medicate. They should seek the advice of their physician. Gastrointestinal tract symptoms (dyspepsia, nausea, vomiting) are the most common side effects of ASA and are more likely with chronic, high dose administration. Enteric coating will reduce this reaction by inhibiting the release of ASA in the stomach. However this also delays activity. Enteric coated tablets must be swallowed whole, not broken or chewed. Gastric distress will also be reduced by taking ASA with milk, food or a full glass of water. A full glass of water and remaining upright for 15 to 30 minutes also decreases the chance of a tablet becoming lodged in the esophagus where it can cause irritation. Slight blood loss may occur in about 70% of patients, often with no symptoms, and may result in iron deficiency with prolonged use. Massive Gl bleeding is rare. Alcohol and other gastric irritants will exacerbate GI upset. Acetaminophen can be recommended since it does not usually cause significant GI upset.
Salicylates cross the placenta. ASA use during the last trimester of pregnancy increases the risk of maternal,
fetal and neonatal hemorrhage. It may also cause premature closure of the fetal ductus arteriosis and lengthen
the duration of pregnancy and parturition time. Acetaminophen is considered safe for short-term use in
late pregnancy .
Salicylates are excreted in breast milk and have the potential for infant side effects with high or prolonged dosage. Acetaminophen also passes into breast milk but is considered safe for short-term use.
Patients with severe asthma or asthma and allergies associated with nasal polyps have an increased risk of
ASA induced bronchospasm and sensitivity to ASA.
Some patients sensitive to ASA may be sensitive to other NSAIDS including OTC ibuprofen, as well as tartrazine dye.
Acetaminophen can be taken as an alternative. However, 5% of patients with salicylate sensitivity are also sensitive to acetaminophen, especially those who have dermatologic reactions.
Salicylates reduce renal function. This can be critical in patients with reduced renal function or if efficient renal function is required (sever hypertension, severe congestive heart failure).
Salicylates may cause complications in patients with Systemic Lupus Erythematous.
Bismuth Subsalicylate contains salicylates. Two tablets or two tablespoons of suspension provides the equivalent of a 325 mg ASA tablet. This is important in patients already on salicylate therapy and for any precautions applying to ASA.