NSAID Poisoning: Aspirin

Aspirin is a strong non-steroidal anti-inflammatory drug (NSAID). Another name is Acetyl Salicylic Acid. It is extracted from Willow-bark. It is a weak organic acid.

It is taken orally, absorbed in Stomach and first part of duodenum. Well absorbed in acidic media as it is less ionized there. It binds strongly with plasma protein. So, it is well distributed trough out the body. It can cross blood-brain barrier (BBB) and placental barrier. It is metabolized by the liver and excreted by the kidneys. 10% Aspirin is excreted in unchanged form as Salicylate.

Aspirin, as with many older drugs, has proven to be useful in many conditions. Despite its well-known toxicity it is widely used since Physicians are familiar with its properties. Indications for its use includes:

• Fever (except Dengue Fever)
• Pain (specially useful for some form rheumatoid arthritis, osteoid osteoma, chronic pain etc)
• Migraine
• Rheumatic fever
• Pericarditis
• Coronary artery disease
• Kawasaki disease
• Acute myocardial infarction
• Stroke- as secondary prevention. (to prevent recurrence)

• Gastric irritation
  • Gastrointestinal bleeding
  • Duodenal ulceration
  • Nausea, vomiting
  • Hyperacidity
  • Perforation
  • Hematemesis, malena
• Impaired blood clotting
• Allergic manifestation
• CNS toxicity
  • Confusion
  • Dizziness
  • Vertigo
• Reye’s syndrome (hence it is no lonrg used n case of children in flu like conditions.)
• Salicylism
• Respiratory alkalosis
• Metabolic acidosis
• Dehydration
• Undetected blood loss.

• Hypersensitivity.
• Acute exaggeration of Peptic Ulcer Disease.
• Coagulation or bleeding disorder; such as Hemophilia.
• Liver insufficiency
• Last trimester of pregnancy.
• Kidney disease.
• Immediate after or before labour.
• Baby below one year having Pyrexia.
• Menstruating women (because Aspirin causes profuse bleeding)

• Acute: When a single large dose is taken. Acute overdose has a mortality rate of 2%.
• Chronic: When supratherapeutic doses are taken over a period of time. It is more commonly lethal with a mortality rate of 25%. Chronic overdose may be severe in case of children and female.

In case of mild intoxication:

• Nausea, vomiting
• Abdominal pain
• Lethargy
• Tinnitus
• Dizziness

In case of severe intoxication:

• Hyperthermia
• Tachypnoea
• Respiratory alkalosis
• Metabolic acidosis
• Hyperkalemia
• Hypoglycemia
• Confusion
• Seizure
• Cerebral oedema
• Coma

In case of Aspirin poisoning, activated charcoal is given orally for gastric decontamination as because activated charcoal interrupts absorption of aspirin. Stomach pump is only done if patient has taken overdose of aspirin up to 1 hour previously. No anti-dote to Salicylate poisoning is available.

Patient must be given

• Intravenous KCl to counteract Hypokalemia.
• Intravenous glucose to restore blood sugar.
• Benzodiazepines in case of any seizure activity.
• Maintenance of water and electrolyte balance.
• Sodium Bi-Carbonate, to counteract acidification of blood and body fluid.
• Hemodialysis to remove Salicylate from Blood.
• Psychiatric evaluation in case of Suicidal attempts.

If Aspirin is taken more than 8mg/day it may cause CNS toxicity which is known as Salicylism.

• Initially:
  • Headache
  • Tinnitus
  • Confusion
  • Nausea, vomiting
  • Epigastric pain
  • Diarrhea
• In sever cases:
  • Hallucination
  • Unconsciousness

• Hospitalization: Any sort of drug overdose is considered as poisoning. Immediate hospitalization is a must for any poisoning case. Because, it is regarded as Police case.
• Drug History: Taking the history of nae of drugs, time of taking, amount taken, duration, signs & symptoms present etc.
• Stoppage of all medicine.
• If it is within 2 to 4 hours, stomach wash can be given by a mixture of water & potassium permanganate
• Activated charcoal can be given to reduce absorption from GIT.
• Intravenous diuretics should be given to increase excretion of drugs by the kidneys.
• Alkalization of kidneys can be done by Sodium Bi Carbonate

Patient of any poisoning case is to be monitored properly. A slight change in the parameters; such as blood glucose, serum electrolyte etc may indicate any sort of fatality and needed to be corrected as soon as possible. Psychotherapy is a must in case of any suicidal attempt. And all sort of drugs should be kept out of the reach of the children.