See Treatment of salicylate poisoning
Contained in aspirin, sodium salicylate, methyl salicylate, oil of wintergreen
Found in analgesic products (also in keratolytics and heat rubs)
Chronic toxicity frequently missed diagnosis (up to 50%)
Mortality/Morbidity - particularly high if untreated
Appropriate treatment involves good supportive care, adequate re-hydration with urinary alkalisation and potassium replacement
ACUTE TOXICITY | CHRONIC TOXICITY | |
Epidemiology | Accidental ingestion in
children
Suicide attempts in adults |
Accidental in the elderly with
rheumatological conditions (decreased renal function, large Vd, decreased protein, often dehydrated, poor nutrition) |
Chronology | may be preceded by relatively asymptomatic period | often gradual and insidious (ingestion over > 12 hrs) |
Symptoms |
Initial
Later
|
|
Differential Diagnosis |
Acute iron poisoning Reyes syndrome Diabetic ketoacidosis Sepsis Meningitis |
|
Salicylate levels | >40 mg/dL or 2.3 mmol/L is toxic |
Correlates poorly with clinical effects |
Treatment | Treat if symptomatic or > 150mg/kg or > 40mg/dL | Treat on symptoms |
Mortality |
1% | 25% |
Dehydration (may be severe in chronic toxicity)
Hypo-natraemia
Hypo-kalaemia
Hypo-calcaemia/Seizures/Tetany
Seizures, Cerebral oedema, Coma, and Death
Coagulopathy
Pylorospasm, decreased gastro intestinal motility (acute)
Gastric erosions, Iron deficiency anaemia (in chronic)
ARDS (chronic severe toxicity)
Renal tubular damage (rare)
Haemolysis (rare)
Bronchospasm, hypotension
Rhinitis, Nasal polyps (chronic)
Ferric chloride test - Add few drops of 10% ferric chloride1 ml to patient's urine (brown purple = salicylate)
Type, Amount, Time of ingestion, Chronicity
Acute toxicity likely with > 150 mg/kg (4ml of oil wintergreen)
Large overdose has prolonged peak effect
Serum levels/Ingested Dose
Dose (mg/kg)
Serum Level (mg/dL)
Estimated Severity
Clinical Features
<150
<40
Minimal GIT intolerance, bleeding
Hypersensitivity
Acute gout150-300
40-110
Mild-to-moderate Tinnitus, deafness, vertigo
Nausea & vomiting, dehydration
Fever
Hyperventilation
Respiratory alkalosis/Metabolic acidosis
300-500
110-160
Serious Circulatory collapse
Coma
Coagulopathy>500
>160
Potentially lethal cerebral oedema Complicating issues
Co-ingestants (inhibits respiratory compensation of metabolic acidosis)
Complicating medical conditions (chronic renal failure => early dialysis)
Pregnancy (fetus at risk)
See Treatment of salicylate poisoning
See Basic Pharmacology of Salicylates